1
|
Allen AM, Olive LN, Gonzalez Franco PA, Barua SR, Allen WD, Schaefer HF. Fulminic acid: a quasibent spectacle. Phys Chem Chem Phys 2024. [PMID: 39248729 DOI: 10.1039/d4cp02700k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2024]
Abstract
Fulminic acid (HCNO) played a critical role in the early development of organic chemistry, and chemists have sought to discern the structure and characteristics of this molecule and its isomers for over 200 years. The mercurial nature of the extremely flat H-C-N bending potential of fulminic acid, with a nearly vanishing harmonic vibrational frequency at linearity, remains enigmatic and refractory to electronic structure theory, as dramatic variation with both orbital basis set and electron correlation method is witnessed. To solve this problem using rigorous electronic wavefunction methods, we have employed focal point analyses (FPA) to ascertain the ab initio limit of optimized linear and bent geometries, corresponding vibrational frequencies, and the HCN + O(3P) → HCNO reaction energy. Electron correlation treatments as extensive as CCSDT(Q), CCSDTQ(P), and even CCSDTQP(H) were employed, and complete basis set (CBS) extrapolations were performed using the cc-pCVXZ (X = 4-6) basis sets. Core electron correlation, scalar relativistic effects (MVD1), and diagonal Born-Oppenheimer corrections (DBOC) were all included and found to contribute significantly in determining whether vibrationless HCNO is linear or bent. At the all-electron (AE) CCSD(T)/CBS level, HCNO is a linear molecule with ω5(H-C-N bend) = 120 cm-1. However, composite AE-CCSDT(Q)/CBS computations give an imaginary frequency (51i cm-1) at the linear optimized geometry, leading to an equilibrium structure with an H-C-N angle of 173.9°. Finally, at the AE-CCSDTQ(P)/CBS level, HCNO is once again linear with ω5 = 45 cm-1, and inclusion of both MVD1 and DBOC effects yields ω5 = 32 cm-1. A host of other topics has also been investigated for fulminic acid, including the dependence of re and ωi predictions on a variety of CBS extrapolation formulas, the question of multireference character, the N-O bond energy and enthalpy of formation, and issues that give rise to the quasibent appellation.
Collapse
Affiliation(s)
- Ashley M Allen
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
| | - Laura N Olive
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
| | | | - Shiblee R Barua
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
| | - Wesley D Allen
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
| |
Collapse
|
2
|
Rishi V, Cole-Filipiak NC, Ramasesha K, McCaslin LM. Excited state electronic structure of dimethyl disulfide involved in photodissociation at ∼200 nm. Phys Chem Chem Phys 2024. [PMID: 39240347 DOI: 10.1039/d4cp02505a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
Dimethyl disulfide (DMDS), one of the smallest organic molecules with an S-S bond, serves as a model system for understanding photofragmentation in polypeptides and proteins. Prior studies of DMDS photodissociation excited at ∼266 nm and ∼248 nm have elucidated the mechanisms of S-S and C-S bond cleavage, which involve the lowest excited electronic states S1 and S2. Far less is known about the dissociation mechanisms and electronic structure of relevant excited states of DMDS excited at ∼200 nm. Herein we present calculations of the electronic structure and properties of electronic states S1-S6 accessed when DMDS is excited at ∼200 nm. Our analysis includes a comparison of theoretical and experimental UV spectra, as well as theoretically predicted one-dimensional cuts through the singlet and triplet potential energy surfaces along the S-S and C-S bond dissociation coordinates. Finally, we present calculations of spin-orbit coupling constants at the Franck-Condon geometry to assess the likelihood of ultrafast intersystem crossing. We show that choosing an accurate yet computationally efficient electronic structure method for calculating the S0-S6 potential energy surfaces along relevant dissociation coordinates is challenging due to excited states with doubly excited character and/or mixed Rydberg-valence character. Our findings demonstrate that the extended multi-state complete active space second-order perturbation theory (XMS-CASPT2) balances this computational efficiency and accuracy, as it captures both the Rydberg character of states in the Franck-Condon region and multiconfigurational character toward the bond-dissociation limits. We compare the performance of XMS-CASPT2 to a new variant of equation of motion coupled cluster theory with single, double, and perturbative triple corrections, EOM-CCSD(T)(a)*, finding that EOM-CCSD(T)(a)* significantly improves the treatment of doubly excited states compared to EOM-CCSD, but struggles to quantitatively capture asymptotic energies along bond dissociation coordinates for these states.
Collapse
Affiliation(s)
- Varun Rishi
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA.
| | - Neil C Cole-Filipiak
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA.
| | - Krupa Ramasesha
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA.
| | - Laura M McCaslin
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA.
| |
Collapse
|
3
|
Knysh I, Lipparini F, Blondel A, Duchemin I, Blase X, Loos PF, Jacquemin D. Reference CC3 Excitation Energies for Organic Chromophores: Benchmarking TD-DFT, BSE/ GW, and Wave Function Methods. J Chem Theory Comput 2024. [PMID: 39237472 DOI: 10.1021/acs.jctc.4c00906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
To expand the QUEST database of highly accurate vertical transition energies, we consider a series of large organic chromogens ubiquitous in dye chemistry, such as anthraquinone, azobenzene, BODIPY, and naphthalimide. We compute, at the CC3 level of theory, the singlet and triplet vertical transition energies associated with the low-lying excited states. This leads to a collection of more than 120 new highly accurate excitation energies. For several singlet transitions, we have been able to determine CCSDT transition energies with a compact basis set, finding minimal deviations from the CC3 values for most states. Subsequently, we employ these reference values to benchmark a series of lower-order wave function approaches, including the popular ADC(2) and CC2 schemes, as well as time-dependent density-functional theory (TD-DFT), both with and without applying the Tamm-Dancoff approximation (TDA). At the TD-DFT level, we evaluate a large panel of global, range-separated, local, and double hybrid functionals. Additionally, we assess the performance of the Bethe-Salpeter equation (BSE) formalism relying on both G0W0 and evGW quasiparticle energies evaluated from various starting points. It turns out that CC2 and ADC(2.5) are the most accurate models among those with respective O ( N 5 ) and O ( N 6 ) scalings with system size. In contrast, CCSD does not outperform CC2. The best performing exchange-correlation functionals include BMK, M06-2X, M06-SX, CAM-B3LYP, ωB97X-D, and LH20t, with average deviations of approximately 0.20 eV or slightly below. Errors on vertical excitation energies can be further reduced by considering double hybrids. Both SOS-ωB88PP86 and SOS-ωPBEPP86 exhibit particularly attractive performances with overall quality on par with CC2, whereas PBE0-DH and PBE-QIDH are only slightly less efficient. BSE/evGW calculations based on Kohn-Sham starting points have been found to be particularly effective for singlet transitions, but much less for their triplet counterparts.
Collapse
Affiliation(s)
- Iryna Knysh
- Nantes Université, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via Moruzzi 3, 56124 Pisa, Italy
| | - Aymeric Blondel
- Nantes Université, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
| | - Ivan Duchemin
- Université Grenoble Alpes, CEA, IRIG-MEM-L Sim, 38054 Grenoble, France
| | - Xavier Blase
- Université Grenoble Alpes, CNRS, Institut NEEL, F-38042 Grenoble, France
| | - Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Denis Jacquemin
- Nantes Université, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
- Institut Universitaire de France (IUF), F-75005 Paris, France
| |
Collapse
|
4
|
Flint AR, Westbrook BR, Fortenberry RC. Theoretical Rotational and Vibrational Spectral Data for the Hypermagnesium Oxide Species Mg 2O and Mg 2O . Chemphyschem 2024; 25:e202400479. [PMID: 38801234 DOI: 10.1002/cphc.202400479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/22/2024] [Accepted: 05/26/2024] [Indexed: 05/29/2024]
Abstract
While magnesium is astronomically observed in small molecules, it largely serves as a contributor to silicate grains, though how these grains form is not well-understood. The smallest hypermagnesium oxide compounds (Mg2 ${{}_{2}}$ O/Mg2 ${{}_{2}}$ O+ ${{}^{+}}$ ) may play a role in silicate formation, but little vibrational reference data exist. As such, anharmonic spectroscopic data are computed forX ˜ 1 Σ g + ${{{\tilde{\rm {X}}}}^1 {\rm{\Sigma }}_g^+ }$ Mg2 ${{}_{2}}$ O,a ˜ 1 Σ u + ${{{\tilde{\rm {a}}}}^1 {\rm{\Sigma }}_u^+ }$ Mg2 ${{}_{2}}$ O, andX ˜ 2 Σ g + ${{{\tilde{\rm {X}}}}^2 {\rm{\Sigma }}_g^+ }$ Mg2 ${{}_{2}}$ O+ ${{}^{+}}$ using quartic force fields (QFFs). Explicitly-correlated coupled-cluster QFFs for the neutral species perform well, implying that full multireference treatment may not be necessary for such systems if enough electron correlation is included. Equation-of-motion ionization potential (EOMIP) methods forX ˜ 2 Σ g + ${{{\tilde{\rm {X}}}}^2 {\rm{\Sigma }}_g^+ }$ Mg2 ${{}_{2}}$ O+ ${{}^{+}}$ QFFs circumvent previous symmetry breaking issues even in explicitly-correlated coupled-cluster results, motivating the need for EOMIP treatments at minimum for such systems. All three species are found to have high-intensity vibrational frequencies. Even so, the highly intense frequency (X ˜ 1 Σ g + ${{{\tilde{\rm {X}}}}^1 {\rm{\Sigma }}_g^+ }$ Mg2 ${{}_{2}}$ O: 894.7 cm-1/11.18 μm;a ˜ 1 Σ u + ${{{\tilde{\rm {a}}}}^1 {\rm{\Sigma }}_u^+ }$ Mg2 ${{}_{2}}$ O: 915.0 cm-1/10.91 μm) for either neutral state may be astronomically obscured by the polycyclic aromatic hydrocarbon 11.2 μm band. Mg2 ${{}_{2}}$ O+ ${{}^{+}}$ may be less susceptible to such obfuscation, and itsν 1 ${{\nu }_{1}}$ intensity is computed to be a massive 4793 km mol-1.
Collapse
Affiliation(s)
- Athena R Flint
- Department of Chemistry & Biochemistry, University of Mississippi, University, MS 38655, USA
| | - Brent R Westbrook
- The Open Force Field Initiative, Open Molecular Software Foundation, Davis, CA 95616, USA
| | - Ryan C Fortenberry
- Department of Chemistry & Biochemistry, University of Mississippi, University, MS 38655, USA
| |
Collapse
|
5
|
Leitner J, Dempwolff AL, Dreuw A. Fourth-Order Algebraic Diagrammatic Construction for Electron Detachment and Attachment: The IP- and EA-ADC(4) Methods. J Phys Chem A 2024. [PMID: 39213621 DOI: 10.1021/acs.jpca.4c03037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
We present a non-Dyson fourth-order algebraic diagrammatic construction formulation of the electron propagator, featuring the distinct IP- and EA-ADC(4) schemes for the treatment of ionization and electron attachment processes. The algebraic expressions have been derived automatically using the intermediate state representation approach and implemented in the Q-Chem quantum-chemical program package. The performance of the novel methods is assessed with respect to high-level reference data for ionization potentials and electron affinities of closed- and open-shell systems. While only minor improvements over the corresponding third-order methods are observed for one-hole ionization and one-particle electron attachment processes from closed-shell systems (MAEIP-ADC(4) = 0.27 eV and MAEEA-ADC(4) = 0.05 eV), a significantly enhanced performance is found in case of open-shell reference states (MAEIP-ADC(4) = 0.11 eV and MAEEA-ADC(4) = 0.02 eV). A particularly appealing feature of the novel methods is their accurate treatment of satellite transitions. For closed-shell reference states, we obtain accuracies of MAEIP-ADC(4) = 0.81 eV and MAEEA-ADC(4) = 0.27 eV, while in case of open-shell reference states, mean absolute errors of MAEIP-ADC(4) = 0.15 eV and MAEEA-ADC(4) = 0.27 eV are found.
Collapse
Affiliation(s)
- Jonas Leitner
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Adrian L Dempwolff
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| |
Collapse
|
6
|
Zhao T, Matthews DA. Analytic Gradients for Equation-of-Motion Coupled Cluster with Single, Double, and Perturbative Triple Excitations. J Chem Theory Comput 2024. [PMID: 39214857 DOI: 10.1021/acs.jctc.4c00752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Understanding the process of molecular photoexcitation is crucial in various fields, including drug development, materials science, photovoltaics, and more. The electronic vertical excitation energy is a critical property, for example in determining the singlet-triplet gap of chromophores. However, a full understanding of excited-state processes requires additional explorations of the excited-state potential energy surface and electronic properties, which is greatly aided by the availability of analytic energy gradients. Owing to its robust high accuracy over a wide range of chemical problems, equation-of-motion coupled cluster with single and double excitations (EOM-CCSD) is a powerful method for predicting excited-state properties, and the implementation of analytic gradients of many EOM-CCSD variants (excitation energies, ionization potentials, electron attachment energies, etc.) along with numerous successful applications highlights the flexibility of the method. In specific cases where a higher level of accuracy is needed or in more complex electronic structures, the inclusion of triple excitations becomes essential, for example, in the EOM-CCSD* approach of Saeh and Stanton. In this work, we derive and implement for the first time the analytic gradients of EOMEE-CCSD*, which also provides a template for analytic gradients of related excited-state methods with perturbative triple excitations. The capabilities of analytic EOMEE-CCSD* gradients are illustrated by several representative examples.
Collapse
Affiliation(s)
- Tingting Zhao
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75205, United States
| | - Devin A Matthews
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75205, United States
| |
Collapse
|
7
|
Thorpe JH, Windom ZW, Bartlett RJ, Matthews DA. Factorized Quadruples and a Predictor of Higher-Level Correlation in Thermochemistry. J Phys Chem A 2024. [PMID: 39194317 DOI: 10.1021/acs.jpca.4c04460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2024]
Abstract
Coupled cluster theory has had a momentous impact on the ab initio prediction of molecular properties, and remains a staple ingratiate in high-accuracy thermochemical model chemistries. However, these methods require inclusion of at least some connected quadruple excitations, which generally scale at best as O ( N 9 ) with the number of basis functions. It is very difficult to predict, a priori, the effect correlation of past CCSD(T) on a given reaction energy. The purpose of this work is to examine cost-effective quadruple corrections based on the factorization theorem of the many-body perturbation theory that may address these challenges. We show that the O ( N 7 ) factorized CCSD(TQf) method introduces minimal error to predicted correlation and reaction energies as compared to the O ( N 9 ) CCSD(TQ). Further, we examine the performance of Goodson's continued fraction method in the estimation of CCSDT(Q)Λ contributions to reaction energies as well as a "new" method related to %TAE[(T)] that we refer to as a scaled perturbation estimator. We find that the scaled perturbation estimator based upon CCSD(TQf)/cc-pVDZ is capable of predicting CCSDT(Q)Λ/cc-pVDZ contributions to reaction energies with an average error of 0.07 kcal mol-1 and an L2D of 0.52 kcal mol-1 when applied to a test-suite of nearly 3000 reactions. This offers a means by which to reliably "ballpark" how important post-CCSD(T) contributions are to reaction energies while incurring no more than CCSD(T) formal cost and a little mental math.
Collapse
Affiliation(s)
- James H Thorpe
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Zachary W Windom
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
| | - Rodney J Bartlett
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
| | - Devin A Matthews
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| |
Collapse
|
8
|
Lu T. A comprehensive electron wavefunction analysis toolbox for chemists, Multiwfn. J Chem Phys 2024; 161:082503. [PMID: 39189657 DOI: 10.1063/5.0216272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Accepted: 08/07/2024] [Indexed: 08/28/2024] Open
Abstract
Analysis of electron wavefunction is a key component of quantum chemistry investigations and is indispensable for the practical research of many chemical problems. After more than ten years of active development, the wavefunction analysis program Multiwfn has accumulated very rich functions, and its application scope has covered numerous aspects of theoretical chemical research, including charge distribution, chemical bond, electron localization and delocalization, aromaticity, intramolecular and intermolecular interactions, electronic excitation, and response property. This article systematically introduces the features and functions of the latest version of Multiwfn and provides many representative examples. Through this article, readers will be able to fully understand the characteristics and recognize the unique value of Multiwfn. The source code and precompiled executable files of Multiwfn, as well as the manual containing a detailed introduction to theoretical backgrounds and very rich tutorials, can all be downloaded for free from the Multiwfn website (http://sobereva.com/multiwfn).
Collapse
Affiliation(s)
- Tian Lu
- Beijing Kein Research Center for Natural Sciences, Beijing 100024, People's Republic of China
| |
Collapse
|
9
|
Egorov O, Rey M, Viglaska D, Nikitin AV. Rovibrational Line Lists of Triplet and Singlet Methylene. J Phys Chem A 2024; 128:6960-6971. [PMID: 39119864 DOI: 10.1021/acs.jpca.4c04205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
The methylene molecule (CH2) is a short-lived radical with lacking data on its spectral line intensities. Although the lifetime of CH2 is extremely short under Earth's conditions, it exists in a free form in interstellar media. CH2 is an important intermediate species in chemical reactions associated with the formation and destruction of complex hydrocarbons. We present the first rovibrational line lists of CH2 in its ground triplet and first excited singlet electronic state. To this end, our previously developed accurate ab initio potential energy surface (PES) was used for the ground electronic triplet state [Egorov et al. J. Comp. Chem. 2024. V. 45. (2). P. 83] while a new PES for the singlet state was constructed in this work using the single-reference coupled cluster approach [CCSD(T)] combined with the extrapolation to the complete basis set (CBS) limit based on the correlation-consistent orbital basis sets with the core-valence electron correlation effects [aug-cc-pCVXZ, X = T, Q, 5, and 6]. In addition, the contributions to the correlation energy from highly excited Slater determinants [CC(n), n = 3-5] were included as well as the scalar relativistic effects and DBOC. The most accurate description of the infrared band origins of singlet CH2 was thus achieved for the energy range where the impact of the nonadiabatic coupling due to the Renner-Teller effect can be neglected. To obtain the probabilities of the rovibrational transitions, new ab initio DMSs were constructed both for the triplet and singlet CH2 using the CCSD(T)/aug-cc-pCVQZ approach. Finally, the absorption spectra of triplet and singlet methylene were predicted from the variationally computed line lists.
Collapse
Affiliation(s)
- Oleg Egorov
- Laboratory of Theoretical Spectroscopy, V.E. Zuev Institute of Atmospheric Optics SB RAS 1, Akademician Zuev Sq., Tomsk 634055, Russia
- Faculty of Physics, Tomsk State University 36, Lenin Ave., Tomsk 634050, Russia
| | - Michaël Rey
- Groupe de Spectrométrie Moléculaire et Atmosphérique UMR CNRS 7331, UFR Sciences BP 1039, Reims Cedex 2 51687, France
| | - Dominika Viglaska
- Groupe de Spectrométrie Moléculaire et Atmosphérique UMR CNRS 7331, UFR Sciences BP 1039, Reims Cedex 2 51687, France
| | - Andrei V Nikitin
- Laboratory of Theoretical Spectroscopy, V.E. Zuev Institute of Atmospheric Optics SB RAS 1, Akademician Zuev Sq., Tomsk 634055, Russia
| |
Collapse
|
10
|
Iyer GR, Whelpley N, Tiihonen J, Kent PRC, Krogel JT, Rubenstein BM. Force-Free Identification of Minimum-Energy Pathways and Transition States for Stochastic Electronic Structure Theories. J Chem Theory Comput 2024. [PMID: 39172163 DOI: 10.1021/acs.jctc.4c00214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
The accurate mapping of potential energy surfaces (PESs) is crucial to our understanding of the numerous physical and chemical processes mediated by atomic rearrangements, such as conformational changes and chemical reactions, and the thermodynamic and kinetic feasibility of these processes. Stochastic electronic structure theories, e.g., Quantum Monte Carlo (QMC) methods, enable highly accurate total energy calculations that in principle can be used to construct the PES. However, their stochastic nature poses a challenge to the computation and use of forces and Hessians, which are typically required in algorithms for minimum-energy pathway (MEP) and transition state (TS) identification, such as the nudged elastic band (NEB) algorithm and its climbing image formulation. Here, we present strategies that utilize the surrogate Hessian line-search method, previously developed for QMC structural optimization, to efficiently identify MEP and TS structures without requiring force calculations at the level of the stochastic electronic structure theory. By modifying the surrogate Hessian algorithm to operate in path-orthogonal subspaces and at saddle points, we show that it is possible to identify MEPs and TSs by using a force-free QMC approach. We demonstrate these strategies via two examples, the inversion of the ammonia (NH3) molecule and the nucleophilic substitution (SN2) reaction F- + CH3F → FCH3 + F-. We validate our results using Density Functional Theory (DFT)- and Coupled Cluster (CCSD, CCSD(T))-based NEB calculations. We then introduce a hybrid DFT-QMC approach to compute thermodynamic and kinetic quantities, free energy differences, rate constants, and equilibrium constants that incorporates stochastically optimized structures and their energies, and show that this scheme improves upon DFT accuracy. Our methods generalize straightforwardly to other systems and other high-accuracy theories that similarly face challenges computing energy gradients, paving the way for highly accurate PES mapping, transition state determination, and thermodynamic and kinetic calculations at significantly reduced computational expense.
Collapse
Affiliation(s)
- Gopal R Iyer
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Noah Whelpley
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Juha Tiihonen
- Department of Physics, Nanoscience Center, University of Jyväskylä, Jyväskylä 40014, Finland
| | - Paul R C Kent
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jaron T Krogel
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Brenda M Rubenstein
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| |
Collapse
|
11
|
Greiner J, Gauss J, Eriksen JJ. Error Control and Automatic Detection of Reference Active Spaces in Many-Body Expanded Full Configuration Interaction. J Phys Chem A 2024; 128:6806-6818. [PMID: 39099303 DOI: 10.1021/acs.jpca.4c04056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
We present a wide-reaching revamp of the generalized many-body expanded full configuration interaction (MBE-FCI) method. First, we outline how to automatize the selection of reference active spaces, whereby the inherent bias introduced through a manual identification is reduced, also within the context of traditional complete active space methods. Second, we allow for the use of compact orbital clusters as expansion objects, which works to circumvent the unfavorable scaling with the number of orbitals included in the space complementary to the reference orbitals. Finally, we present a new algorithm for ensuring that many-body expansions can be efficiently terminated while conservatively accounting for resulting errors. These developments are all tested on a variety of molecular systems and different orbital representations to illustrate the abilities of our algorithm to produce correlation energies within predetermined error bounds, significantly broadening the overall applicability of the MBE-FCI method.
Collapse
Affiliation(s)
- Jonas Greiner
- Department Chemie, Johannes Gutenberg-Universität Mainz Duesbergweg 10-14, 55128 Mainz, Germany
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz Duesbergweg 10-14, 55128 Mainz, Germany
| | - Janus J Eriksen
- DTU Chemistry, Technical University of Denmark, Kemitorvet Bldg. 206, 2800 Kgs. Lyngby, Denmark
| |
Collapse
|
12
|
Evangelista FA, Li C, Verma P, Hannon KP, Schriber JB, Zhang T, Cai C, Wang S, He N, Stair NH, Huang M, Huang R, Misiewicz JP, Li S, Marin K, Zhao Z, Burns LA. Forte: A suite of advanced multireference quantum chemistry methods. J Chem Phys 2024; 161:062502. [PMID: 39132791 DOI: 10.1063/5.0216512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 06/24/2024] [Indexed: 08/13/2024] Open
Abstract
Forte is an open-source library specialized in multireference electronic structure theories for molecular systems and the rapid prototyping of new methods. This paper gives an overview of the capabilities of Forte, its software architecture, and examples of applications enabled by the methods it implements.
Collapse
Affiliation(s)
- Francesco A Evangelista
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Chenyang Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Prakash Verma
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Kevin P Hannon
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Jeffrey B Schriber
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
- Department of Chemistry and Biochemistry, Iona University, New Rochelle, New York 10801, USA
| | - Tianyuan Zhang
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Chenxi Cai
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Shuhe Wang
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Nan He
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Nicholas H Stair
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Meng Huang
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Renke Huang
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Jonathon P Misiewicz
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Shuhang Li
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Kevin Marin
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Zijun Zhao
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Lori A Burns
- Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| |
Collapse
|
13
|
Zhang C, Peterson KA, Dyall KG, Cheng L. A new computational framework for spinor-based relativistic exact two-component calculations using contracted basis functions. J Chem Phys 2024; 161:054105. [PMID: 39087536 DOI: 10.1063/5.0217762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/14/2024] [Indexed: 08/02/2024] Open
Abstract
A new computational framework for spinor-based relativistic exact two-component (X2C) calculations is developed using contracted basis sets with a spin-orbit contraction scheme. Generally contracted, j-adapted basis sets of p-block elements using primitive functions in the correlation-consistent basis sets are constructed for the X2C Hamiltonian with atomic mean-field spin-orbit integrals (the X2CAMF scheme). The contraction coefficients are taken from atomic X2CAMF Hartree-Fock spinors, thereby following the simple concept of a linear combination of atomic orbitals. Benchmark calculations of spin-orbit splittings, equilibrium bond lengths, and harmonic vibrational frequencies demonstrate the accuracy and efficacy of the j-adapted spin-orbit contraction scheme.
Collapse
Affiliation(s)
- Chaoqun Zhang
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
| | | | - Lan Cheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| |
Collapse
|
14
|
Nakajima Y, Ohmura T, Seino J. Using atomic clustering based on structural and electronic descriptors that consider surrounding environment to evaluate local properties of DFT functionals. J Comput Chem 2024; 45:1870-1879. [PMID: 38686778 DOI: 10.1002/jcc.27375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 04/01/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024]
Abstract
We developed a method for evaluating the accuracies of the local properties of DFT functionals in detail using a clustering method based on machine learning and structural/electronic descriptors. We generated 36 clusters consistent with human intuition using 30,436 carbon atoms from the QM9 dataset. The results were used to evaluate 13C NMR chemical shifts calculated using 84 DFT functionals. Carbon atoms were grouped based on their similar environments, reducing errors within these groups. This enables more accurate assessment of the accuracy using a specific DFT functional. Therefore, the present atomic clustering provides more detailed insight into accuracy verification.
Collapse
Affiliation(s)
- Yuya Nakajima
- Waseda Research Institute for Science and Engineering, Tokyo, Japan
| | - Takuto Ohmura
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Junji Seino
- Waseda Research Institute for Science and Engineering, Tokyo, Japan
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| |
Collapse
|
15
|
Loos PF, Jacquemin D. A mountaineering strategy to excited states: Accurate vertical transition energies and benchmarks for substituted benzenes. J Comput Chem 2024; 45:1791-1805. [PMID: 38661240 DOI: 10.1002/jcc.27358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/09/2024] [Accepted: 02/15/2024] [Indexed: 04/26/2024]
Abstract
In an effort to expand the existing QUEST database of accurate vertical transition energies [Véril et al. WIREs Comput. Mol. Sci. 2021, 11, e1517], we have modeled more than 100 electronic excited states of different natures (local, charge-transfer, Rydberg, singlet, and triplet) in a dozen of mono- and di-substituted benzenes, including aniline, benzonitrile, chlorobenzene, fluorobenzene, nitrobenzene, among others. To establish theoretical best estimates for these vertical excitation energies, we have employed advanced coupled-cluster methods including iterative triples (CC3 and CCSDT) and, when technically possible, iterative quadruples (CC4). These high-level computational approaches provide a robust foundation for benchmarking a series of popular wave function methods. The evaluated methods all include contributions from double excitations (ADC(2), CC2, CCSD, CIS(D), EOM-MP2, STEOM-CCSD), along with schemes that also incorporate perturbative or iterative triples (ADC(3), CCSDR(3), CCSD(T)(a) ⋆ , and CCSDT-3). This systematic exploration not only broadens the scope of the QUEST database but also facilitates a rigorous assessment of different theoretical approaches in the framework of a homologous chemical series, offering valuable insights into the accuracy and reliability of these methods in such cases. We found that both ADC(2.5) and CCSDT-3 can provide very consistent estimates, whereas among less expensive methods SCS-CC2 is likely the most effective approach. Importantly, we show that some lower order methods may offer reasonable trends in the homologous series while providing quite large average errors, and vice versa. Consequently, benchmarking the accuracy of a model based solely on absolute transition energies may not be meaningful for applications involving a series of similar compounds.
Collapse
Affiliation(s)
- Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, France
| | - Denis Jacquemin
- Nantes Université, CNRS, CEISAM UMR 6230, Nantes, France
- Institut Universitaire de France (IUF), Paris, France
| |
Collapse
|
16
|
Conte R, Aieta C, Cazzaniga M, Ceotto M. A Perspective on the Investigation of Spectroscopy and Kinetics of Complex Molecular Systems with Semiclassical Approaches. J Phys Chem Lett 2024; 15:7566-7576. [PMID: 39024505 DOI: 10.1021/acs.jpclett.4c01338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
In this Perspective we show that semiclassical methods provide a rigorous hierarchical way to study the vibrational spectroscopy and kinetics of complex molecular systems. The time averaged approach to spectroscopy and the semiclassical transition state theory for kinetics, which have been first adopted and then further developed in our group, provide accurate quantum results on rigorous physical grounds and can be applied even when dealing with a large number of degrees of freedom. In spectroscopy, the multiple coherent, divide-and-conquer, and adiabatically switched semiclassical approaches have practically permitted overcoming issues related to the convergence of results. In this Perspective we demonstrate the possibility of studying the semiclassical vibrational spectroscopy of a molecule adsorbed on an anatase (101) surface, a system made of 51 atoms. In kinetics, the semiclassical transition state theory is able to account for anharmonicity and the coupling between the reactive and bound modes. Our group has developed this technique for practical applications involving the study of phenomena like kinetic isotope effect, heavy atom tunneling, and elusive conformer lifetimes. Here, we show that our multidimensional anharmonic quantum approach is able to tackle on-the-fly the thermal kinetic rate constant of a 135 degree-of-freedom system. Overall, semiclassical methods open up the possibility to describe at the quantum mechanical level systems characterized by hundreds of degrees of freedom leading to the accurate spectroscopic and kinetic description of biomolecules and complex molecular systems.
Collapse
Affiliation(s)
- Riccardo Conte
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
| | - Chiara Aieta
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
| | - Marco Cazzaniga
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
| | - Michele Ceotto
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
| |
Collapse
|
17
|
Manna A, Jangid B, Pant R, Dutta AK. Efficient State-Specific Natural Orbital Based Equation of Motion Coupled Cluster Method for Core-Ionization Energies: Theory, Implementation, and Benchmark. J Chem Theory Comput 2024. [PMID: 39073757 DOI: 10.1021/acs.jctc.4c00546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
We have implemented a reduced-cost partial triples correction scheme to the equation of motion coupled cluster method for core-ionization energy based on state-specific natural orbitals. The second-order Algebraic Diagrammatic Construction (ADC) method is used to generate the state-specific natural orbital, which provides quicker convergence of the core-IP value with respect to the size of the virtual space than that observed in standard MP2-based natural orbitals. The error due to truncation of the virtual orbital can be reduced by using a perturbative correction. The accuracy of the method can be controlled by a single threshold, and there is a black box to use. The inclusion of the partial triples correction in the natural orbital based EOM-CCSD method greatly improves the agreement of the results with the experiment. The efficiency of the present implementation is demonstrated by calculating the core-ionization energy of a molecule containing 60 atoms and more than 2000 basis functions.
Collapse
Affiliation(s)
- Amrita Manna
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Bhavnesh Jangid
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Rakesh Pant
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| |
Collapse
|
18
|
Vidal L, Nottoli T, Lipparini F, Cancès E. Geometric Optimization of Restricted-Open and Complete Active Space Self-Consistent Field Wave Functions. J Phys Chem A 2024. [PMID: 39073092 DOI: 10.1021/acs.jpca.4c03213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
We explore Riemannian optimization methods for Restricted-Open-shell Hartree-Fock (ROHF) and Complete Active Space Self-Consistent Field (CASSCF) methods. After showing that ROHF and CASSCF can be reformulated as optimization problems on so-called "flag manifolds", we review Riemannian optimization basics and their application to these specific problems. We compare these methods to traditional ones and find robust convergence properties without fine-tuning of numerical parameters. Our study suggests that Riemannian optimization is a valuable addition to orbital optimization for ROHF and CASSCF, warranting further investigation.
Collapse
Affiliation(s)
- Laurent Vidal
- CERMICS, Ecole des Ponts and Inria Paris, 6 & 8 Avenue Blaise Pascal, 77455 Marne-la-Vallée, France
| | - Tommaso Nottoli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Eric Cancès
- CERMICS, Ecole des Ponts and Inria Paris, 6 & 8 Avenue Blaise Pascal, 77455 Marne-la-Vallée, France
| |
Collapse
|
19
|
Berquist E, Dumi A, Upadhyay S, Abarbanel OD, Cho M, Gaur S, Cano Gil VH, Hutchison GR, Lee OS, Rosen AS, Schamnad S, Schneider FSS, Steinmann C, Stolyarchuk M, Vandezande JE, Zak W, Langner KM. cclib 2.0: An updated architecture for interoperable computational chemistry. J Chem Phys 2024; 161:042501. [PMID: 39051837 DOI: 10.1063/5.0216778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 07/01/2024] [Indexed: 07/27/2024] Open
Abstract
Interoperability in computational chemistry is elusive, impeded by the independent development of software packages and idiosyncratic nature of their output files. The cclib library was introduced in 2006 as an attempt to improve this situation by providing a consistent interface to the results of various quantum chemistry programs. The shared API across programs enabled by cclib has allowed users to focus on results as opposed to output and to combine data from multiple programs or develop generic downstream tools. Initial development, however, did not anticipate the rapid progress of computational capabilities, novel methods, and new programs; nor did it foresee the growing need for customizability. Here, we recount this history and present cclib 2, focused on extensibility and modularity. We also introduce recent design pivots-the formalization of cclib's intermediate data representation as a tree-based structure, a new combinator-based parser organization, and parsed chemical properties as extensible objects.
Collapse
Affiliation(s)
- Eric Berquist
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Amanda Dumi
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Shiv Upadhyay
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Omri D Abarbanel
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA
| | - Minsik Cho
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Sagar Gaur
- MarkovML 23, Geary St. Suite 600, San Francisco, California 94108, USA
- International Institute of Information Technology, Prof. CR Rao Road Gachibowli, Hyderabad 500032, Telangana, India
| | | | - Geoffrey R Hutchison
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA
| | - Oliver S Lee
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St. Andrews KY16 9ST, United Kingdom
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St. Andrews KY16 9SS, United Kingdom
| | - Andrew S Rosen
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | | | | | - Casper Steinmann
- Department of Chemistry and Bioscience, Aalborg University, DK-9230 Aalborg, Denmark
| | | | | | - Weronika Zak
- Department of Computer Science, Loughborough University, Epinal Way, Loughborough, Leicestershire LE11 3TU, United Kingdom
| | | |
Collapse
|
20
|
Alessandrini S, Melosso M, Bizzocchi L, Barone V, Puzzarini C. The Semiexperimental Approach at Work: Equilibrium Structure of Radical Species. J Phys Chem A 2024; 128:5833-5855. [PMID: 38991181 DOI: 10.1021/acs.jpca.4c01758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
The so-called semiexperimental (SE) approach is a powerful technique for obtaining highly accurate equilibrium structures for isolated systems. This Featured Article describes its extension to open-shell species, thus providing the first systematic investigation on radical equilibrium geometries to be used for benchmarking purposes. The small yet significant database obtained demonstrates that there is no reduction in accuracy when moving from closed-shell species to radicals. We also provide an extension of the applicability of the SE approach to medium-/large-sized radicals by exploiting the so-called "Lego-brick" approach, which is based on the assumption that a molecular system can be seen as formed by smaller fragments for which the SE equilibrium structure is available. In this Featured Article we show that this model can be successfully applied also to open-shell species.
Collapse
Affiliation(s)
- Silvia Alessandrini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, I-40126 Bologna, Italy
| | - Mattia Melosso
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, I-40126 Bologna, Italy
| | - Luca Bizzocchi
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, I-40126 Bologna, Italy
| | | | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, I-40126 Bologna, Italy
| |
Collapse
|
21
|
Chen T, Zhang C, Cheng L, Ng KB, Malbrunot-Ettenauer S, Flambaum VV, Lasner Z, Doyle JM, Yu P, Conn CJ, Zhang C, Hutzler NR, Jayich AM, Augenbraun B, DeMille D. Relativistic Exact Two-Component Coupled-Cluster Study of Molecular Sensitivity Factors for Nuclear Schiff Moments. J Phys Chem A 2024. [PMID: 39047199 DOI: 10.1021/acs.jpca.4c02640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Relativistic exact two-component coupled-cluster calculations of molecular sensitivity factors for nuclear Schiff moments (NSMs) are reported. We focus on molecules containing heavy nuclei, especially octupole-deformed nuclei. Analytic relativistic coupled-cluster gradient techniques are used and serve as useful tools for identifying candidate molecules that sensitively probe for physics beyond the Standard Model in the hadronic sector. Notably, these tools enable straightforward "black-box" calculations. Two competing chemical mechanisms that contribute to the NSM are analyzed, illuminating the physics of ligand effects on NSM sensitivity factors.
Collapse
Affiliation(s)
- Tianxiang Chen
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Chaoqun Zhang
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Lan Cheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kia Boon Ng
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Stephan Malbrunot-Ettenauer
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Physics, University of Toronto, Toronto M5S 1A7, Canada
| | - Victor V Flambaum
- School of Physics, University of New South Wales, Sydney 2052, Australia
| | - Zack Lasner
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, United States
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, United States
| | - Phelan Yu
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, United States
| | - Chandler J Conn
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, United States
| | - Chi Zhang
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, United States
| | - Nicholas R Hutzler
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, United States
| | - Andrew M Jayich
- Department of Physics, University of California, Santa Barbara, California 93106, United States
| | - Benjamin Augenbraun
- Department of Chemistry, Williams College, 47 Lab Campus Drive, Williamstown, Massachusetts 01267, United States
| | - David DeMille
- Department of Physics, University of Chicago, Chicago, Illinois 60637, United States
| |
Collapse
|
22
|
Fauser S, Drontschenko V, Ochsenfeld C, Görling A. Accurate NMR Shieldings with σ-Functionals. J Chem Theory Comput 2024; 20:6028-6036. [PMID: 38967385 DOI: 10.1021/acs.jctc.4c00512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
In recent years, density-functional methods relying on a new type of fifth-rung correlation functionals called σ-functionals have been introduced. σ-Functionals are technically closely related to the random phase approximation and require the same computational effort but yield distinctively higher accuracies for reaction and transition state energies of main group chemistry and even outperform double-hybrid functionals for these energies. In this work, we systematically investigate how accurate σ-functionals can describe nuclear magnetic resonance (NMR) shieldings. It turns out that σ-functionals yield very accurate NMR shieldings, even though in their optimization, exclusively, energies are employed as reference data and response properties such as NMR shieldings are not involved at all. This shows that σ-functionals combine universal applicability with accuracy. Indeed, the NMR shieldings from a σ-functional using input orbitals and eigenvalues from Kohn-Sham calculations with the exchange-correlation functional of Perdew, Burke and Ernzerhof (PBE) turned out to be the most accurate ones among the NMR shieldings calculated with various density-functional methods including methods using double-hybrid functionals. That σ-functionals can be used for calculating both reliable energies and response properties like NMR shieldings characterizes them as all-purpose functionals, which is appealing from an application point of view.
Collapse
Affiliation(s)
- Steffen Fauser
- Lehrstuhl für Theoretische Chemie, Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
| | - Viktoria Drontschenko
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU), D-81377 Munich, Germany
| | - Christian Ochsenfeld
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU), D-81377 Munich, Germany
- Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - Andreas Görling
- Lehrstuhl für Theoretische Chemie, Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
- Erlangen National High Performance Computing Center (NHR@FAU), Martensstr. 1, D-91058 Erlangen, Germany
| |
Collapse
|
23
|
Mosely JJ, Tschumper GS. Probing the Effects of Size and Charge on the Monohydration and Dihydration of SiF 5- and SiF 62- via Comparisons with BF 4- and PF 6. J Phys Chem A 2024; 128:5637-5645. [PMID: 38976798 DOI: 10.1021/acs.jpca.4c03430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
This study systematically examines the interactions of the trigonal bipyramidal silicon pentafluoride and octahedral silicon hexafluoride anions with either one or two water molecules, (SiF5-(H2O)n and SiF62-(H2O)n, respectively, where n = 1, 2). Full geometry optimizations and subsequent harmonic vibrational frequency computations are performed using the CCSD(T) ab initio method with a triple-ζ correlation consistent basis set augmented with diffuse functions on all non-hydrogen atoms (cc-pVTZ for H and aug-cc-pVTZ for Si, O, and F; denoted as haTZ). Two monohydrate and six dihydrate minima have been identified for the SiF5-(H2O)n systems, whereas one monohydrate and five dihydrate minima have been identified for the SiF62-(H2O)n systems. Both monohydrated anions have a minimum in which the water molecule adopts a symmetric double ionic hydrogen bond (DIHB) motif with C2v symmetry. However, a second unique monohydrate minimum has been identified for SiF5- in which the water molecule adopts an asymmetric DIHB motif along the edge of the trigonal bipyramidal anion between one axial and one equatorial F atom. This Cs structure is more than 2 kcal mol-1 lower in energy than the C2v local minimum at the CCSD(T)/haTZ level of theory. While the interactions between the solvent and ionic solute are quite strong for the monohydrated anions (electronic dissociation energies of ≈12 and ≈24 kcal mol-1 for the SiF5-(H2O)1 and SiF62-(H2O)1 global minima, respectively), these values are nearly perfectly doubled for the dihydrates, with the lowest-energy SiF5-(H2O)2 and SiF62-(H2O)2 minima exhibiting dissociation energies of ≈24 and ≈47 kcal mol-1, respectively. Structures that form hydrogen bonds between the solvating water molecules also exhibit the largest shifts in the harmonic OH stretching frequencies for the waters of hydration. These shifts can exceed -100 cm-1 for the SiF5-(H2O)2 minimum and -300 cm-1 for the SiF62-(H2O)2 minimum relative to an isolated H2O molecule at the CCSD(T)/haTZ level of theory. This work also corrects the OH stretching frequency shifts for two dihydrate minima of PF6- that were previously erroneously reported ( J. Phys. Chem. A 2020, 124, 8744-8752, DOI: 10.1021/acs.jpca.0c06466).
Collapse
Affiliation(s)
- Jacquelyn J Mosely
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677-1848, United States
| | - Gregory S Tschumper
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677-1848, United States
| |
Collapse
|
24
|
Goodlett SM, Kitzmiller NL, Turney JM, Schaefer HF. MolSym: A Python package for handling symmetry in molecular quantum chemistry. J Chem Phys 2024; 161:024107. [PMID: 38984965 DOI: 10.1063/5.0216738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/20/2024] [Indexed: 07/11/2024] Open
Abstract
A consideration of the point group symmetry of molecules is often advantageous from a computational efficiency standpoint and sometimes necessary for the correct treatment of chemical physics problems. Many modern electronic structure software packages include a treatment of symmetry, but these are sometimes incomplete or unusable outside of that program's environment. Therefore, we have developed the MolSym package for handling molecular symmetry and its associated functionalities to provide a platform for including symmetry in the implementation and development of other methods. Features include point group detection, molecule symmetrization, arbitrary generation of symmetry element sets and character tables, and symmetry adapted linear combinations of real spherical harmonic basis functions, Cartesian displacement coordinates, and internal coordinates. We present some of the advantages of using molecular symmetry as achieved by MolSym, particularly with respect to Hartree-Fock theory, and the reduction of finite difference displacements in gradient/Hessian computations. This package is designed to be easily integrated into other software development efforts and may be extended to further symmetry applications.
Collapse
Affiliation(s)
- Stephen M Goodlett
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Nathaniel L Kitzmiller
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Justin M Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| |
Collapse
|
25
|
Blaschke S, Stopkowicz S, Pausch A. Efficient approximate screening techniques for integrals over London atomic orbitals. J Chem Phys 2024; 161:024117. [PMID: 38995080 DOI: 10.1063/5.0217246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 06/19/2024] [Indexed: 07/13/2024] Open
Abstract
Efficient integral screening techniques are essential for the investigation of extended molecular structures. This work presents a critical assessment of well-established approximate screening techniques and extends them for integrals over London atomic orbitals, which are required in the presence of strong, external magnetic fields. Through the examination of helium clusters in such extreme environments, we demonstrate that seemingly straightforward extensions of field-free screening techniques as proposed in the recent literature can lead to significant errors. To rectify this, we propose two alternative screening techniques that lead to the desired speedups while still maintaining strict error control.
Collapse
Affiliation(s)
- Simon Blaschke
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
- Fachrichtung Chemie, Universität des Saarlandes, D-66123 Saarbrücken, Germany
| | - Stella Stopkowicz
- Fachrichtung Chemie, Universität des Saarlandes, D-66123 Saarbrücken, Germany
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033, N-0315 Oslo, Norway
| | - Ansgar Pausch
- Theoretical Chemistry, Vrije Universiteit Amsterdam, 1081HV Amsterdam, The Netherlands
| |
Collapse
|
26
|
Antalík A, Levy A, Kvedaravičiūtė S, Johnson SK, Carrasco-Busturia D, Raghavan B, Mouvet F, Acocella A, Das S, Gavini V, Mandelli D, Ippoliti E, Meloni S, Carloni P, Rothlisberger U, Olsen JMH. MiMiC: A high-performance framework for multiscale molecular dynamics simulations. J Chem Phys 2024; 161:022501. [PMID: 38990116 DOI: 10.1063/5.0211053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/15/2024] [Indexed: 07/12/2024] Open
Abstract
MiMiC is a framework for performing multiscale simulations in which loosely coupled external programs describe individual subsystems at different resolutions and levels of theory. To make it highly efficient and flexible, we adopt an interoperable approach based on a multiple-program multiple-data (MPMD) paradigm, serving as an intermediary responsible for fast data exchange and interactions between the subsystems. The main goal of MiMiC is to avoid interfering with the underlying parallelization of the external programs, including the operability on hybrid architectures (e.g., CPU/GPU), and keep their setup and execution as close as possible to the original. At the moment, MiMiC offers an efficient implementation of electrostatic embedding quantum mechanics/molecular mechanics (QM/MM) that has demonstrated unprecedented parallel scaling in simulations of large biomolecules using CPMD and GROMACS as QM and MM engines, respectively. However, as it is designed for high flexibility with general multiscale models in mind, it can be straightforwardly extended beyond QM/MM. In this article, we illustrate the software design and the features of the framework, which make it a compelling choice for multiscale simulations in the upcoming era of exascale high-performance computing.
Collapse
Affiliation(s)
- Andrej Antalík
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Andrea Levy
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Sonata Kvedaravičiūtė
- DTU Chemistry, Technical University of Denmark (DTU), DK-2800 Kongens Lyngby, Denmark
| | - Sophia K Johnson
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | - Bharath Raghavan
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Department of Physics, RWTH Aachen University, Aachen 52074, Germany
| | - François Mouvet
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | - Sambit Das
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Vikram Gavini
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Davide Mandelli
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Emiliano Ippoliti
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Simone Meloni
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie (DOCPAS), Università degli Studi di Ferrara (Unife), I-44121 Ferrara, Italy
| | - Paolo Carloni
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Department of Physics, RWTH Aachen University, Aachen 52074, Germany
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | |
Collapse
|
27
|
Kossoski F, Boggio-Pasqua M, Loos PF, Jacquemin D. Reference Energies for Double Excitations: Improvement and Extension. J Chem Theory Comput 2024; 20:5655-5678. [PMID: 38885174 DOI: 10.1021/acs.jctc.4c00410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
In the realm of photochemistry, the significance of double excitations (also known as doubly excited states), where two electrons are concurrently elevated to higher energy levels, lies in their involvement in key electronic transitions essential in light-induced chemical reactions as well as their challenging nature from the computational theoretical chemistry point of view. Based on state-of-the-art electronic structure methods (such as high-order coupled-cluster, selected configuration interaction, and multiconfigurational methods), we improve and expand our prior set of accurate reference excitation energies for electronic states exhibiting a substantial amount of double excitations [Loos et al. J. Chem. Theory Comput. 2019, 15, 1939]. This extended collection encompasses 47 electronic transitions across 26 molecular systems that we separate into two distinct subsets: (i) 28 "genuine" doubly excited states where the transitions almost exclusively involve doubly excited configurations and (ii) 19 "partial" doubly excited states which exhibit a more balanced character between singly and doubly excited configurations. For each subset, we assess the performance of high-order coupled-cluster (CC3, CCSDT, CC4, and CCSDTQ) and multiconfigurational methods (CASPT2, CASPT3, PC-NEVPT2, and SC-NEVPT2). Using as a probe the percentage of single excitations involved in a given transition (%T1) computed at the CC3 level, we also propose a simple correction that reduces the errors of CC3 by a factor of 3, for both sets of excitations. We hope that this more complete and diverse compilation of double excitations will help future developments of electronic excited-state methodologies.
Collapse
Affiliation(s)
- Fábris Kossoski
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Martial Boggio-Pasqua
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Denis Jacquemin
- Nantes Université, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
- Institut Universitaire de France (IUF), F-75005 Paris, France
| |
Collapse
|
28
|
Puzzarini C, Alessandrini S. Carbamic acid and its dimer: A computational study. J Comput Chem 2024. [PMID: 38970400 DOI: 10.1002/jcc.27442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 07/08/2024]
Abstract
A recent work by Marks et al. on the formation of carbamic acid in NH3 $$ {}_3 $$ -CO2 $$ {}_2 $$ interstellar ices pointed out its stability in the gas phase and the concomitant production of its dimer. Prompted by these results and the lack of information on these species, we have performed an accurate structural, energetic and spectroscopic investigation of carbamic acid and its dimer. For the former, the structural and spectroscopic characterization employed composite schemes based on coupled cluster (CC) calculations that account for the extrapolation to the complete basis set limit and core correlation effects. A first important outcome is the definitive confirmation of the nonplanarity of carbamic acid, then followed by an accurate estimate of its rotational and vibrational spectroscopy parameters. As far as the carbamic acid dimer is concerned, the investigation started from the identification of its most stable forms. For them, structure and vibrational properties have been evaluated using density functional theory, while a composite scheme rooted in CC theory has been employed for the energetic characterization. Our results allowed us to provide a better interpretation of the feature observed in the recent experiment mentioned above.
Collapse
Affiliation(s)
- Cristina Puzzarini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
| | - Silvia Alessandrini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
| |
Collapse
|
29
|
Owens A. A highly accurate potential energy surface for carbonyl sulphide (OCS): how important are the ab initio calculations? Phys Chem Chem Phys 2024; 26:17684-17694. [PMID: 38869020 DOI: 10.1039/d4cp01205d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
Ab initio quantum chemical methods can produce accurate molecular potential energy surfaces (PESs) capable of predicting the fundamental vibrational wavenumbers to within 1 cm-1. However, for high-resolution applications this is simply not good enough and empirical refinement is necessary, i.e. adjusting the PES to better match laboratory spectroscopic data. Here, the impact of the underlying ab initio calculations is rigorously investigated within the context of empirical refinement. For carbonyl sulphide (OCS), state-of-the-art electronic structure calculations are employed to construct higher- and lower-level ab initio PESs, which are then empirically refined in near-identical procedures. The initial ab initio calculations are shown to considerably affect the accuracy of the final refined PES, with an order-of-magnitude improvement in computed rotation-vibration energy levels achieved for OCS. In demonstrating this, the most accurate PES of the electronic ground state of OCS is produced, reproducing the fundamentals with a root-mean-square error (RMSE) of 0.004 cm-1, and 884 rovibrational energy levels below 14 000 cm-1 with an RMSE of 0.060 cm-1.
Collapse
Affiliation(s)
- Alec Owens
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT, London, UK.
| |
Collapse
|
30
|
Nonne M, Melosso M, Tonolo F, Bizzocchi L, Alessandrini S, Guillemin JC, Dore L, Puzzarini C. Tracing Prebiotic Molecules: Rotational Spectroscopy of Deuterated Glycolaldehyde and ( Z)-1,2-Ethenediol. J Phys Chem A 2024; 128:4850-4858. [PMID: 38842131 DOI: 10.1021/acs.jpca.4c02533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Glycolaldehyde, an important prebiotic molecule, along with its monodeuterated species and its higher energy tautomer, (Z)-1,2-ethenediol, has been detected in the interstellar medium. Although the elemental D/H ratio in the universe is only ∼1.6 × 10-5, the deuterium relative abundance in interstellar molecules might be by far larger than this. As such, it provides a remarkable and almost unique diagnostic tool. In particular, it might help elucidate the reaction mechanisms that lead to the formation of the so-called complex organic molecules. It is therefore crucial to extend the census of the interstellar deuterated molecules. To this aim, in this work, we present for the first time a spectroscopic investigation of the rotational spectra of the CHDOD-CHO bideuterated variant of glycolaldehyde and of mono- and bideuterated species of (Z)-1,2-ethenediol (CHOD═CHOD, CHOD═CHOH, and CHOH═CHOD rotamers). For each species, more than a hundred transitions have been assigned. Their analysis led to the accurate determination of all rotational constants as well as quartic and sextic centrifugal distortion terms, thus providing spectroscopic line catalogs suitable for supporting astronomical searches. In addition, the rotational constants of the bideuterated glycolaldehyde isotopologue studied in this work allowed us to improve the semiexperimental equilibrium structure determination for this molecule.
Collapse
Affiliation(s)
- Michela Nonne
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Naples, Italy
| | - Mattia Melosso
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Francesca Tonolo
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Luca Bizzocchi
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Silvia Alessandrini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Jean-Claude Guillemin
- Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR6226, F-35000 Rennes, France
| | - Luca Dore
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| |
Collapse
|
31
|
Bonah L, Schlemmer S, Guillemin JC, Harding ME, Thorwirth S. On the Spectroscopy of Phosphaalkynes: Millimeter- and Submillimeter-Wave Study of C 2H 5CP. J Phys Chem A 2024; 128:4859-4866. [PMID: 38857201 DOI: 10.1021/acs.jpca.4c02566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Ethyl phosphaethyne, C2H5CP, has been characterized spectroscopically in the gas phase for the first time, employing millimeter- and submillimeter-wave spectroscopy in the frequency regime from 75 to 760 GHz. Spectroscopic detection and analysis was guided by high-level quantum-chemical calculations of molecular structures and force fields performed at the coupled-cluster singles and doubles level extended by a perturbative correction for the contribution from triple excitations, CCSD(T), in combination with large basis sets. Besides the parent isotopologue, the three singly substituted 13C species were observed in natural abundance up to frequencies as high as 500 GHz. Despite the comparably low astronomical abundance of phosphorus, phosphaalkynes, R-CP, such as C2H5CP are promising candidates for future radio astronomical detection.
Collapse
Affiliation(s)
- Luis Bonah
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln 50937, Germany
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln 50937, Germany
| | - Jean-Claude Guillemin
- Université de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR─UMR6226, Rennes 35000, France
| | - Michael E Harding
- Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Kaiserstr. 12, Karlsruhe 76131, Germany
| | - Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln 50937, Germany
| |
Collapse
|
32
|
Sahoo NP, Franke PR, Stanton JF. On the performance of composite schemes in determining equilibrium molecular structures. J Comput Chem 2024; 45:1419-1427. [PMID: 38450778 DOI: 10.1002/jcc.27312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/10/2023] [Accepted: 12/12/2023] [Indexed: 03/08/2024]
Abstract
Determination of equilibrium molecular structures is an essential ingredient in predicting spectroscopic parameters that help in identifying molecular carriers of microwave transitions. Here, the performance of two different ab initio composite approaches for obtaining equilibrium structures, "energy scheme" and "geometry scheme," is explored and compared to semi-experimental equilibrium structures. This study is performed for a set of 11 molecules which includes diatomics, linear triatomics, and a few non-linear molecules. The ab initio calculations were performed using three tiers of composite chemical recipes. The current results show that as the overall rigor of calculation is increased, the semi-experimental and the ab initio numbers agree to within 0.0003 Å for all molecules in the test set. The composite approach based on correcting the potential energy surface (energy scheme) and the one based on correcting the geometry directly (geometry scheme) show excellent agreement with each other. This work represents a step toward development of efficient and highly accurate procedures for computing ab initio equilibrium structures.
Collapse
Affiliation(s)
- Nitai P Sahoo
- Department of Chemistry, University of Florida, Gainesvillle, Florida, USA
| | - Peter R Franke
- Department of Chemistry, University of Florida, Gainesvillle, Florida, USA
| | - John F Stanton
- Department of Chemistry, University of Florida, Gainesvillle, Florida, USA
| |
Collapse
|
33
|
Qian Y, Nguyen TL, Franke PR, Stanton JF, Lester MI. Nonstatistical Unimolecular Decay of the CH 2OO Criegee Intermediate in the Tunneling Regime. J Phys Chem Lett 2024; 15:6222-6229. [PMID: 38838341 DOI: 10.1021/acs.jpclett.4c01401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Unimolecular decay of the formaldehyde oxide (CH2OO) Criegee intermediate proceeds via a 1,3 ring-closure pathway to dioxirane and subsequent rearrangement and/or dissociation to many products including hydroxyl (OH) radicals that are detected. Vibrational activation of jet-cooled CH2OO with two quanta of CH stretch (17-18 kcal mol-1) leads to unimolecular decay at an energy significantly below the transition state barrier of 19.46 ± 0.25 kcal mol-1, refined utilizing a high-level electronic structure method HEAT-345(Q)Λ. The observed unimolecular decay rate of 1.6 ± 0.4 × 106 s-1 is 2 orders of magnitude slower than that predicted by statistical unimolecular reaction theory using several different models for quantum mechanical tunneling. The nonstatistical behavior originates from excitation of a CH stretch vibration that is orthogonal to the heavy atom motions along the reaction coordinate and slow intramolecular vibrational energy redistribution due to the sparse density of states.
Collapse
Affiliation(s)
- Yujie Qian
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Thanh Lam Nguyen
- Department of Chemistry, University of Florida, Gainesville, Florida 32611 United States
| | - Peter R Franke
- Department of Chemistry, University of Florida, Gainesville, Florida 32611 United States
| | - John F Stanton
- Department of Chemistry, University of Florida, Gainesville, Florida 32611 United States
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| |
Collapse
|
34
|
Greiner J, Gianni I, Nottoli T, Lipparini F, Eriksen JJ, Gauss J. MBE-CASSCF Approach for the Accurate Treatment of Large Active Spaces. J Chem Theory Comput 2024; 20:4663-4675. [PMID: 38809011 DOI: 10.1021/acs.jctc.4c00388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
We present a novel implementation of the complete active space self-consistent field (CASSCF) method that makes use of the many-body expanded full configuration interaction (MBE-FCI) method to incrementally approximate electronic structures within large active spaces. On the basis of a hybrid first-order algorithm employing both Super-CI and quasi-Newton strategies for the optimization of molecular orbitals, we demonstrate both computational efficacy and high accuracy of the resulting MBE-CASSCF method. We assess the performance of our implementation on a set of established numerical tests before applying MBE-CASSCF in the investigation of the triplet-quintet spin gap of iron(II) porphyrin with active spaces as large as 50 electrons in 50 orbitals.
Collapse
Affiliation(s)
- Jonas Greiner
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, Mainz 55128, Germany
| | - Ivan Gianni
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Tommaso Nottoli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Janus J Eriksen
- DTU Chemistry, Technical University of Denmark, Kemitorvet Bldg. 206, Kgs. Lyngby 2800, Denmark
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, Mainz 55128, Germany
| |
Collapse
|
35
|
Marie A, Loos PF. Reference Energies for Valence Ionizations and Satellite Transitions. J Chem Theory Comput 2024; 20:4751-4777. [PMID: 38776293 PMCID: PMC11171335 DOI: 10.1021/acs.jctc.4c00216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 05/24/2024]
Abstract
Upon ionization of an atom or a molecule, another electron (or more) can be simultaneously excited. These concurrently generated states are called "satellites" (or shakeup transitions) as they appear in ionization spectra as higher-energy peaks with weaker intensity and larger width than the main peaks associated with single-particle ionizations. Satellites, which correspond to electronically excited states of the cationic species, are notoriously challenging to model using conventional single-reference methods due to their high excitation degree compared to the neutral reference state. This work reports 42 satellite transition energies and 58 valence ionization potentials (IPs) of full configuration interaction quality computed in small molecular systems. Following the protocol developed for the quest database [Véril, M.; Scemama, A.; Caffarel, M.; Lipparini, F.; Boggio-Pasqua, M.; Jacquemin, D.; and Loos, P.-F. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2021, 11, e1517], these reference energies are computed using the configuration interaction using a perturbative selection made iteratively (CIPSI) method. In addition, the accuracy of the well-known coupled-cluster (CC) hierarchy (CC2, CCSD, CC3, CCSDT, CC4, and CCSDTQ) is gauged against these new accurate references. The performances of various approximations based on many-body Green's functions (GW, GF2, and T-matrix) for IPs are also analyzed. Their limitations in correctly modeling satellite transitions are discussed.
Collapse
Affiliation(s)
- Antoine Marie
- Laboratoire de Chimie et Physique
Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Pierre-François Loos
- Laboratoire de Chimie et Physique
Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| |
Collapse
|
36
|
Windom ZW, Claudino D, Bartlett RJ. A new "gold standard": Perturbative triples corrections in unitary coupled cluster theory and prospects for quantum computing. J Chem Phys 2024; 160:214113. [PMID: 38832905 DOI: 10.1063/5.0202567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/16/2024] [Indexed: 06/06/2024] Open
Abstract
A major difficulty in quantum simulation is the adequate treatment of a large collection of entangled particles, synonymous with electron correlation in electronic structure theory, with coupled cluster (CC) theory being the leading framework for dealing with this problem. Augmenting computationally affordable low-rank approximations in CC theory with a perturbative account of higher-rank excitations is a tractable and effective way of accounting for the missing electron correlation in those approximations. This is perhaps best exemplified by the "gold standard" CCSD(T) method, which bolsters the baseline CCSD with the effects of triple excitations using considerations from many-body perturbation theory (MBPT). Despite this established success, such a synergy between MBPT and the unitary analog of CC theory (UCC) has not been explored. In this work, we propose a similar approach wherein converged UCCSD amplitudes are leveraged to evaluate energy corrections associated with triple excitations, leading to the UCCSD[T] method. In terms of quantum computing, this correction represents an entirely classical post-processing step that improves the energy estimate by accounting for triple excitation effects without necessitating new quantum algorithm developments or increasing demand for quantum resources. The rationale behind this choice is shown to be rigorous by studying the properties of finite-order UCC energy functionals, and our efforts do not support the addition of the fifth-order contributions as in the (T) correction. We assess the performance of these approaches on a collection of small molecules and demonstrate the benefits of harnessing the inherent synergy between MBPT and UCC theories.
Collapse
Affiliation(s)
- Zachary W Windom
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA
- Quantum Information Science Section, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Daniel Claudino
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Rodney J Bartlett
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA
| |
Collapse
|
37
|
Jangid B, Hermes MR, Gagliardi L. Core Binding Energy Calculations: A Scalable Approach with the Quantum Embedding-Based Equation-of-Motion Coupled-Cluster Method. J Phys Chem Lett 2024; 15:5954-5963. [PMID: 38810243 DOI: 10.1021/acs.jpclett.4c00957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
We investigated the use of density matrix embedding theory to facilitate the computation of core ionization energies (IPs) of large molecules at the equation-of-motion coupled-cluster singles doubles with perturbative triples (EOM-CCSD*) level in combination with the core-valence separation (CVS) approximation. The unembedded IP-CVS-EOM-CCSD* method with a triple-ζ basis set produced ionization energies within 1 eV of experiment with a standard deviation of ∼0.2 eV for the core65 data set. The embedded variant contributed very little systematic error relative to the unembedded method, with a mean unsigned error of 0.07 eV and a standard deviation of ∼0.1 eV, in exchange for accelerating the calculations by many orders of magnitude. By employing embedded EOM-CC methods, we computed the core ionization energies of the uracil hexamer, doped fullerene, and chlorophyll molecule, utilizing up to ∼4000 basis functions within 1 eV from experimental values. Such calculations are not currently possible with the unembedded EOM-CC method.
Collapse
Affiliation(s)
- Bhavnesh Jangid
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Matthew R Hermes
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Laura Gagliardi
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| |
Collapse
|
38
|
Grazioli L, Schleicher LT, Stopkowicz S, Gauss J. Theoretical prediction of closed-shell paramagnetism for scandium and yttrium hydride. J Comput Chem 2024; 45:1215-1223. [PMID: 38334014 DOI: 10.1002/jcc.27305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/19/2023] [Accepted: 12/23/2023] [Indexed: 02/10/2024]
Abstract
Following chemical intuition, one would expect that all closed-shell molecules are diamagnetic. However, it is known that this is not the case for some second-row hydrides with low-lying unoccupied π orbitals due to an unquenching of the total angular momentum in the presence of an external magnetic field. In this article, the transition-metal hydrides ScH and YH are investigated, assuming a similar unquenching effect involving low-lying unoccupied π and δ orbitals formed from the metal d orbitals rather than the p orbitals. We are comparing results obtained with various quantum-chemical methods (HF, CCSD, CCSD(T), CCSDT) and basis sets. The obtained positive values for the magnetizabilities clearly indicate paramagnetic behavior. Vibrational effects on the magnetizability tensor are also considered, but these effects are small and do not change the overall conclusion that both ScH and YH are further examples for closed-shell paramagnetism.
Collapse
Affiliation(s)
- Laura Grazioli
- Department Chemie, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Luca T Schleicher
- Department Chemie, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Stella Stopkowicz
- Fachrichtung Chemie, Universität des Saarlandes, Saarbrücken, Germany
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, Oslo, Norway
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| |
Collapse
|
39
|
Shaalan Alag A, Szalay PG, Tajti A. Ab initio investigation of excited state charge transfer pathways in differently capped bithiophene cages. J Comput Chem 2024; 45:1078-1086. [PMID: 38241483 DOI: 10.1002/jcc.27307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/27/2023] [Accepted: 12/15/2023] [Indexed: 01/21/2024]
Abstract
The electronic excitations of conformationally constrained bithiophene cage systems as previously investigated by Lewis et al. (J. Am. Chem. Soc. 143, 18548 (2021)) are revisited, employing the correlated ab initio Scaled Opposite-Spin Algebraic Diagrammatic Construction Second Order electronic structure method. Quantitative descriptors are determined to assess the extent of charge transfer between the bithiophene moieties and the capping domains, represented by either phenyl or triazine groups. The investigation substantiates intrinsic differences in the photophysical behavior of these two structural variants and reveals the presence of lower-energy excited states characterized by noteworthy charge transfer contributions in the triazine cage system. The manifestation of this charge transfer character is discernible even at the Franck-Condon geometry, persisting throughout the relaxation of the excited state. By examining isolated monomer building blocks, we confirm the existence of analogous charge transfer contributions in their excitations. Employing this methodological approach facilitates the prospective identification of potential wall/cap chromophore pairs, wherein charge transfer pathways can be accessed within the energetically favorable regime.
Collapse
Affiliation(s)
- Ahmed Shaalan Alag
- Laboratory of Theoretical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Péter G Szalay
- Laboratory of Theoretical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Tajti
- Laboratory of Theoretical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| |
Collapse
|
40
|
Lechner MH, Papadopoulos A, Sivalingam K, Auer AA, Koslowski A, Becker U, Wennmohs F, Neese F. Code generation in ORCA: progress, efficiency and tight integration. Phys Chem Chem Phys 2024; 26:15205-15220. [PMID: 38767596 DOI: 10.1039/d4cp00444b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
An improved version of ORCA's automated generator environment (ORCA-AGE II) is presented. The algorithmic improvements and the move to C++ as the programming language lead to a performance gain of up to two orders of magnitude compared to the previously developed PYTHON toolchain. Additionally, the restructured modular design allows for far more complex code engines to be implemented readily. Importantly, we have realised an extremely tight integration with the ORCA host program. This allows for a workflow in which only the wavefunction Ansatz is part of the source code repository while all actual high-level code is generated automatically, inserted at the appropriate place in the host program before it is compiled and linked together with the hand written code parts. This construction ensures longevity and uniform code quality. Furthermore the new developments allow ORCA-AGE II to generate parallelised production-level code for highly complex theories, such as fully internally contracted multireference coupled-cluster theory (fic-MRCC) with an enormous number of contributing tensor contractions. We also discuss the automated implementation of nuclear gradients for arbitrary theories. All these improvements enable the implementation of theories that are too complex for the human mind and also reduce development times by orders of magnitude. We hope that this work enables researchers to concentrate on the intellectual content of the theories they develop rather than be concerned with technical details of the implementation.
Collapse
Affiliation(s)
- Marvin H Lechner
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Anastasios Papadopoulos
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Kantharuban Sivalingam
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Alexander A Auer
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Axel Koslowski
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Ute Becker
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Frank Wennmohs
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| | - Frank Neese
- Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
| |
Collapse
|
41
|
Santalucia D, Bondanza M, Lipparini F, Ripszam M, Rossi N, Mandoli A. Breaking the Rules: On the Relative Stability of Some Methylencyclopropane and Methylcyclopropene Derivatives. Chemistry 2024; 30:e202400431. [PMID: 38483818 DOI: 10.1002/chem.202400431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Indexed: 04/11/2024]
Abstract
The structure of the spirocyclic product obtained by reacting catechol with 1,1-dichloro-2-(chloromethyl)cyclopropane is shown by NMR and X-ray analysis to be that of a 2-methylcyclopropene (MeCP), instead of the previously reported 2-methylenecyclopropane (MCP) one. The study of the equilibration between the two isomeric forms by experimental and computational means (including both Density Functional Theory - DFT - and Coupled Cluster with single, double, and perturbative triple excitations - CCSD(T) - calculations) revealed that, at variance with most of the alkylidenecyclopropane/alkylcyclopropene systems described to date, for the compounds of the present study the MeCP derivative is more stable by≈ 2.5-3.0 Kcal mol-1 than the MCP one. The extension of the DFT and CCSD(T) study to other spiro-MCP/MeCP pairs suggests that the origin of the unexpected shift of the equilibrium position can be tracked back to a combination of electronic and ring-strain effects. These findings lead to re-think a long-standing, and substantially undisputed belief in the area of unsaturated cyclopropane derivatives.
Collapse
Affiliation(s)
- Delio Santalucia
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56126, Pisa, Italy
| | - Mattia Bondanza
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56126, Pisa, Italy
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56126, Pisa, Italy
| | - Matyas Ripszam
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56126, Pisa, Italy
| | - Nicolò Rossi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56126, Pisa, Italy
| | - Alessandro Mandoli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56126, Pisa, Italy
| |
Collapse
|
42
|
Ferino-Pérez A, Jagau TC. Ab Initio Computation of Auger Decay in Heavy Metals: Zinc about It. J Phys Chem A 2024; 128:3957-3967. [PMID: 38742917 DOI: 10.1021/acs.jpca.4c01316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
We report the first coupled-cluster study of Auger decay in heavy metals. The zinc atom is used as a case study due to its relevance to the Auger emission properties of the 67Ga radionuclide. Coupled-cluster theory combined with complex basis functions is used to describe the transient nature of the core-ionized zinc atom. We also introduce second-order Møller-Plesset perturbation theory as an alternative method for computing partial Auger decay widths. Scalar-relativistic effects are included in our approach for computing Auger electron energies by means of the spin-free exact two-component one-electron Hamiltonian, while spin-orbit coupling is treated by means of perturbation theory. We center our attention on the K-edge Auger decay of zinc dividing the spectrum into three parts (K-LL, K-LM, and K-MM) according to the shells involved in the decay. The computed Auger spectra are in good agreement with experimental results. The most intense peak is found at an Auger electron energy of 7432 eV, which corresponds to a 1D2 final state arising from K-L2L3 transitions. Our results highlight the importance of relativistic effects for describing Auger decay in heavier nuclei. Furthermore, the effect of a first solvation shell is studied by modeling Auger decay in the hexaaqua-zinc(II) complex. We find that K-edge Auger decay is slightly enhanced by the presence of the water molecules as compared to the bare atom.
Collapse
Affiliation(s)
| | - Thomas-C Jagau
- Department of Chemistry, KU Leuven, B-3001 Leuven, Belgium
| |
Collapse
|
43
|
Wang Q, Sundholm D, Gauss J, Nottoli T, Lipparini F, Kino S, Ukai S, Fukui N, Shinokubo H. Changing aromatic properties through stacking: the face-to-face dimer of Ni(II) bis(pentafluorophenyl)norcorrole. Phys Chem Chem Phys 2024; 26:14777-14786. [PMID: 38716819 DOI: 10.1039/d4cp00968a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Nuclear magnetic resonance (NMR) shielding constants have been calculated for Ni(II) bis(pentafluorophenyl)norcorrole and its face-to-face stacked dimer at the Hartree-Fock (HF), second-order Møller-Plesset perturbation theory (MP2), complete-active-space self-consistent-field (CASSCF) levels as well as at density functional theory (DFT) levels using several functionals. The calculated 1H NMR shielding constants agree rather well with the experimental ones. The shielding constants of N and Ni calculated at DFT, HF, and MP2 levels differ from those obtained in the CASSCF calculations due to near-degeneracy effects at the Ni atom. The calculated magnetically induced current densities show that the monomer is antiaromatic, sustaining a strong global paratropic ring current, and the dimer is aromatic, sustaining a strong diatropic ring current. Qualitatively the same current density is obtained at the employed levels of theory. The most accurate ring-current strengths are probably obtained at the MP2 level. The aromatic dimer has a short intermolecular distance of less than 3 Å. The intermolecular interaction changes the nature of the frontier orbitals leading to a formal double bond between the norcorrole macrocycles.
Collapse
Affiliation(s)
- Qian Wang
- Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55 (A.I. Virtanens plats 1), FIN-00014, Finland.
| | - Dage Sundholm
- Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55 (A.I. Virtanens plats 1), FIN-00014, Finland.
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Tommaso Nottoli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy
| | - Shota Kino
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Shusaku Ukai
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Norihito Fukui
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
- Graduate School of Engineering, Nagoya University, 2JST PRESTO, Japan
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| |
Collapse
|
44
|
Gibbas B, Kaledin M, Kaledin AL. Quantum Monte Carlo Simulations of the Vibrational Wavefunction of the Aromatic Cyclo[10]carbon Using a Full Dimensional Permutationally Invariant Potential Energy Surface. J Phys Chem Lett 2024; 15:5070-5075. [PMID: 38701515 PMCID: PMC11103689 DOI: 10.1021/acs.jpclett.4c00893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/24/2024] [Accepted: 05/01/2024] [Indexed: 05/05/2024]
Abstract
New experimental measurements [Sun et al., Nature 2023, 623, 972] of the cyclic C10 reveal a cumulenic pentagon-like D5h structure at ∼5 K. However, the long-standing presumption that a large zero-point vibrational energy combined with an extremely flat D5h ↔ D10h ↔ D5h isomerization pathway washes out the pentagonal D5h structure and yields a symmetric D10h decagon remains at odds with the experiment. We resolve this issue with our fitting approach based on a bond-order charge-density matrix expressed in permutationally invariant polynomials. We train the model on τHCTH/cc-pVQZ data morphed to reproduce a relativistic all-electron CCSDT(Q)/CBS D5h-D10h potential energy barrier (benchmarked previously by others). Large scale diffusion Monte Carlo simulations in full dimensionality show that the vibrational ground state of C10 has compositional character of more than 96% D5h, fully reflecting the experimental imaging data. Quantum mechanical variational calculations in 1-D further suggest persistence of the D5h symmetry structure at higher temperatures.
Collapse
Affiliation(s)
- Benjamin
D. Gibbas
- Department
of Chemistry & Biochemistry, Kennesaw
State University, 370 Paulding Ave NW, Box # 1203, Kennesaw, Georgia 30144, United States
| | - Martina Kaledin
- Department
of Chemistry & Biochemistry, Kennesaw
State University, 370 Paulding Ave NW, Box # 1203, Kennesaw, Georgia 30144, United States
| | - Alexey L. Kaledin
- Cherry
L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| |
Collapse
|
45
|
Irikura KK. Ab initio spectroscopy and thermochemistry of the platinum hydride ions, PtH+ and PtH. J Chem Phys 2024; 160:184309. [PMID: 38738614 DOI: 10.1063/5.0207505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/26/2024] [Indexed: 05/14/2024] Open
Abstract
Rovibrational levels of low-lying electronic states of the gas-phase, diatomic molecules, PtH+ and PtH-, are computed on potential-energy functions obtained by using a hybrid spin-orbit configuration-interaction procedure. PtH- has a well-separated Σ0++1 ground state, while the first two electronic states of PtH+ (Σ0++1 and 3Δ3) are nearly degenerate. Combining the experimental photoelectron (PE) spectra of PtH- with theoretical photodetachment spectroscopy leads to an improved value for the electron affinity of PtH, EA(PtH) = (1.617 ± 0.015) eV. When PtH- is a product of photodissociation of PtHCO2-, its PE spectrum is broad because of rotational excitation. Temperature-dependent thermodynamic functions and thermochemistry of dissociation are computed from the theoretical energy levels. Previously published energetic quantities for PtH+ and PtH- are revised. The ground 1Σ+ term of PtH+ is not well described using single-reference theory.
Collapse
Affiliation(s)
- Karl K Irikura
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899 , USA
| |
Collapse
|
46
|
Changala PB, McCarthy MC. Rotational Spectrum of the Phenoxy Radical. J Phys Chem Lett 2024:5063-5069. [PMID: 38701387 DOI: 10.1021/acs.jpclett.4c00962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
We report the hyperfine-resolved rotational spectrum of the gas-phase phenoxy radical in the 8-25 GHz frequency range using cavity Fourier transform microwave spectroscopy. A complete assignment of its complex but well-resolved fine and hyperfine splittings yielded a precisely determined set of rotational constants, spin-rotation parameters, and nuclear hyperfine coupling constants. These results are interpreted with support from high-level quantum chemical calculations to gain detailed insight into the distribution of the unpaired π electron in this prototypical resonance-stabilized radical. The accurate laboratory rest frequencies enable studies of the chemistry of phenoxy in both the laboratory and space. The prospects of extending the present experimental and theoretical techniques to investigate the rotational spectra of isotopic variants and structural isomers of phenoxy and other important gas-phase radical intermediates that are yet undetected at radio wavelengths are discussed.
Collapse
Affiliation(s)
- P Bryan Changala
- Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts 02138, United States
| | - Michael C McCarthy
- Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts 02138, United States
| |
Collapse
|
47
|
Puzzarini C, Ye H, Alessandrini S. Isomerism of CH 2 SO : Accurate structural, energetic, and spectroscopic characterization. J Comput Chem 2024; 45:777-786. [PMID: 38116807 DOI: 10.1002/jcc.27283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/24/2023] [Accepted: 11/28/2023] [Indexed: 12/21/2023]
Abstract
A recent work [Ye et al. Mon. Not. R. Astron. Soc. 2023, 525, 1158] on the gas-phase formation of t-HC(O)SH, already detected in the interstellar medium, pointed out that the trans form of HC(S)OH is a potential candidate for astronomical observations. Prompted by these results, theCH 2 SO family of isomers has been investigated from an energetic point of view using a double-hybrid density functional in combination with a partially augmented triple-zeta basis set. This preliminary study showed that the most stable species of the family are the cis and trans forms of HC(O)SH and HC(S)OH. For their structural and spectroscopic characterization, a composite scheme based on coupled cluster (CC) calculations that incorporates up to the quadruple excitations and accounts for the extrapolation to the complete basis set limit and core correlation effects has been employed. This approach opens to the prediction of rotational constants with an accuracy of 0.1%. A hybrid scheme, based on harmonic frequencies computed using the CC singles, doubles and a perturbative treatment of triples method (CCSD(T)) in conjunction with a quadruple-zeta basis set, allowed us to obtain fundamental vibrational frequencies with a mean absolute error of about 1%.
Collapse
Affiliation(s)
- Cristina Puzzarini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
| | - Hexu Ye
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
| | - Silvia Alessandrini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
| |
Collapse
|
48
|
Pandey P, Arandhara M, Houston PL, Qu C, Conte R, Bowman JM, Ramesh SG. Assessing Permutationally Invariant Polynomial and Symmetric Gradient Domain Machine Learning Potential Energy Surfaces for H 3O 2. J Phys Chem A 2024; 128:3212-3219. [PMID: 38624168 PMCID: PMC11056970 DOI: 10.1021/acs.jpca.4c01044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/15/2024] [Accepted: 03/20/2024] [Indexed: 04/17/2024]
Abstract
The singly hydrated hydroxide anion OH-(H2O) is of central importance to a detailed molecular understanding of water; therefore, there is strong motivation to develop a highly accurate potential to describe this anion. While this is a small molecule, it is necessary to have an extensive data set of energies and, if possible, forces to span several important stationary points. Here, we assess two machine-learned potentials, one using the symmetric gradient domain machine learning (sGDML) method and one based on permutationally invariant polynomials (PIPs). These are successors to a PIP potential energy surface (PES) reported in 2004. We describe the details of both fitting methods and then compare the two PESs with respect to precision, properties, and speed of evaluation. While the precision of the potentials is similar, the PIP PES is much faster to evaluate for energies and energies plus gradient than the sGDML one. Diffusion Monte Carlo calculations of the ground vibrational state, using both potentials, produce similar large anharmonic downshift of the zero-point energy compared to the harmonic approximation of the PIP and sGDML potentials. The computational time for these calculations using the sGDML PES is roughly 300 times greater than using the PIP one.
Collapse
Affiliation(s)
- Priyanka Pandey
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Mrinal Arandhara
- Department
of Inorganic and Physical Chemistry, Indian
Institute of Science, Bangalore 560012, India
| | - Paul L. Houston
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United States
- Department
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332, United States
| | - Chen Qu
- Independent
Researcher, Toronto, Ontario M9B0E3, Canada
| | - Riccardo Conte
- Dipartimento
di Chimica, Università degli Studi
di Milano, Milano 20133, Italy
| | - Joel M. Bowman
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Sai G. Ramesh
- Department
of Inorganic and Physical Chemistry, Indian
Institute of Science, Bangalore 560012, India
| |
Collapse
|
49
|
Fouda AEA, Lindblom V, Southworth SH, Doumy G, Ho PJ, Young L, Cheng L, Sorensen SL. Influence of Selective Carbon 1s Excitation on Auger-Meitner Decay in the ESCA Molecule. J Phys Chem Lett 2024; 15:4286-4293. [PMID: 38608168 PMCID: PMC11057383 DOI: 10.1021/acs.jpclett.3c03611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/22/2024] [Accepted: 04/04/2024] [Indexed: 04/14/2024]
Abstract
Two-dimensional spectral mapping is used to visualize how resonant Auger-Meitner spectra are influenced by the site of the initial core-electron excitation and the symmetry of the core-excited state in the trifluoroethyl acetate molecule (ESCA). We observe a significant enhancement of electron yield for excitation of the COO 1s → π* and CF3 1s → σ* resonances unlike excitation at resonances involving the CH3 and CH2 sites. The CF3 1s → π* and CF3 1s → σ* resonance spectra are very different from each other, with the latter populating most valence states equally. Two complementary electronic structure calculations for the photoelectron cross section and Auger-Meitner intensity are shown to effectively reproduce the site- and state-selective nature of the resonant enhancement features. The site of the core-electron excitation and the respective final state hole locality increase the sensistivity of the photoelectron signal at specific functional group sites. This showcases resonant Auger-Meitner decay as a potentially powerful tool for selectively probing structural changes at specific functional group sites of polyatomic molecules.
Collapse
Affiliation(s)
- A. E. A. Fouda
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
- Department
of Physics and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
| | - V. Lindblom
- Department
of Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - S. H. Southworth
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - G. Doumy
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - P. J. Ho
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - L. Young
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
- Department
of Physics and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
| | - L. Cheng
- Department
of Chemistry, Johns Hopkins University, 3400 North Charles St, Baltimore, Maryland 21218, United States
| | - S. L. Sorensen
- Department
of Physics, Lund University, Box 118, 22100 Lund, Sweden
| |
Collapse
|
50
|
Xue Y, Sexton TM, Yang J, Tschumper GS. Systematic analysis of electronic barrier heights and widths for concerted proton transfer in cyclic hydrogen bonded clusters: (HF) n, (HCl) n and (H 2O) n where n = 3, 4, 5. Phys Chem Chem Phys 2024; 26:12483-12494. [PMID: 38619858 DOI: 10.1039/d4cp00422a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The MP2 and CCSD(T) methods are paired with correlation consistent basis sets as large as aug-cc-pVQZ to optimize the structures of the cyclic minima for (HF)n, (HCl)n and (H2O)n where n = 3-5, as well as the corresponding transition states (TSs) for concerted proton transfer (CPT). MP2 and CCSD(T) harmonic vibrational frequencies confirm the nature of each minimum and TS. Both conventional and explicitly correlated CCSD(T) computations are employed to assess the electronic dissociation energies and barrier heights for CPT near the complete basis (CBS) limit for all 9 clusters. Results for (HF)n are consistent with prior studies identifying Cnh and Dnh point group symmetry for the minima and TSs, respectively. Our computations also confirm that CPT proceeds through Cs TS structures for the C1 minima of (H2O)3 and (H2O)5, whereas the process goes through a TS with D2d symmetry for the S4 global minimum of (H2O)4. This work corroborates earlier findings that the minima for (HCl)3, (HCl)4 and (HCl)5 have C3h, S4 and C1 point group symmetry, respectively, and that the Cnh structures are not minima for n = 4 and 5. Moreover, our computations show the TSs for CPT in (HCl)3, (HCl)4 and (HCl)5 have D3h, D2d, and C2 point group symmetry, respectively. At the CCSD(T) CBS limit, (HF)4 and (HF)5 have the smallest electronic barrier heights for CPT (≈15 kcal mol-1 for both), followed by the HF trimer (≈21 kcal mol-1). The barriers are appreciably higher for the other clusters (around 27 kcal mol-1 for (H2O)4 and (HCl)3; roughly 30 kcal mol-1 for (H2O)3, (H2O)5 and (HCl)4; up to 38 kcal mol-1 for (HCl)5). At the CBS limit, MP2 significantly underestimates the CCSD(T) barrier heights (e.g., by ca. 2, 4 and 7 kcal mol-1 for the pentamers of HF, H2O and HCl, respectively), whereas CCSD overestimates these barriers by roughly the same magnitude. Scaling the barrier heights and dissociation energies by the number of fragments in the cluster reveals strong linear relationships between the two quantities and with the magnitudes of the imaginary vibrational frequency for the TSs.
Collapse
Affiliation(s)
- Yuan Xue
- Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677-1848, USA.
| | - Thomas More Sexton
- School of Arts and Sciences, Chemistry University of Mary, Bismark, ND 58504, USA.
| | - Johnny Yang
- Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677-1848, USA.
| | - Gregory S Tschumper
- Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677-1848, USA.
| |
Collapse
|