1
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Martín Santa Daría A, Avila G, Mátyus E. Methane dimer rovibrational states and Raman transition moments. Phys Chem Chem Phys 2024; 26:10254-10264. [PMID: 38497527 DOI: 10.1039/d3cp06222h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Benchmark-quality rovibrational data are reported for the methane dimer from variational nuclear motion computations using an ab initio intermolecular potential energy surface reported by [M. P. Metz et al., Phys. Chem. Chem. Phys., 2019, 21, 13504-13525]. A simple polarizability model is used to compute Raman transition moments that may be relevant for future direct observation of the intermolecular dynamics. Non-negligible ΔK ≠ 0 transition moments arise in this symmetric top system due to strong rovibrational couplings.
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Affiliation(s)
- Alberto Martín Santa Daría
- Departamento de Química Física, University of Salamanca, 37008 Salamanca, Spain
- ELTE, Eötvös Loránd University, Institute of Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary.
| | - Gustavo Avila
- ELTE, Eötvös Loránd University, Institute of Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary.
| | - Edit Mátyus
- ELTE, Eötvös Loránd University, Institute of Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary.
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2
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Schröder B, Rauhut G. From the Automated Calculation of Potential Energy Surfaces to Accurate Infrared Spectra. J Phys Chem Lett 2024; 15:3159-3169. [PMID: 38478898 PMCID: PMC10961845 DOI: 10.1021/acs.jpclett.4c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/20/2024] [Accepted: 02/28/2024] [Indexed: 03/22/2024]
Abstract
Advances in the development of quantum chemical methods and progress in multicore architectures in computer science made the simulation of infrared spectra of isolated molecules competitive with respect to established experimental methods. Although it is mainly the multidimensional potential energy surface that controls the accuracy of these calculations, the subsequent vibrational structure calculations need to be carefully converged in order to yield accurate results. As both aspects need to be considered in a balanced way, we focus on approaches for molecules of up to 12-15 atoms with respect to both parts, which have been automated to some extent so that they can be employed in routine applications. Alternatives to machine learning will be discussed, which appear to be attractive, as long as local regions of the potential energy surface are sufficient. The automatization of these methods is still in its infancy, and the generalization to molecules with large amplitude motions or molecular clusters is far from trivial, but many systems relevant for astrophysical studies are already in reach.
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Affiliation(s)
- Benjamin Schröder
- Institute
of Physical Chemistry, University of Goettingen, Tammannstrasse 6, Göttingen 37077, Germany
| | - Guntram Rauhut
- Institute
for Theoretical Chemistry, University of
Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany
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3
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Derbali E, Ajili Y, Mehnen B, Żuchowski PS, Kędziera D, Al-Mogren MM, Jaidane NE, Hochlaf M. Towards the generation of potential energy surfaces of weakly bound medium-sized molecular systems: the case of benzonitrile-He complex. Phys Chem Chem Phys 2023; 25:30198-30210. [PMID: 37807943 DOI: 10.1039/d3cp02720a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Currently, the explicitly correlated coupled cluster method is used routinely to generate the multi-dimensional potential energy surfaces (mD-PESs) of van der Waals complexes of small molecular systems relevant for atmospheric, astrophysical and industrial applications. Although very accurate, this method is computationally prohibitive for medium and large molecules containing clusters. For instance, the recent detections of complex organic molecules (COMs) in the interstellar medium, such as benzonitrile, revealed the need to establish an accurate enough electronic structure approach to map the mD-PESs of these species interacting with the surrounding gases. As a benchmark, we have treated the case of the polar molecule benzonitrile interacting with helium, where we use post-Hartree-Fock and symmetry-adapted perturbation theory (SAPT) techniques. Accordingly, we show that MP2 and distinguishable-cluster approximation (DCSD) cannot be used for this purpose, whereas accurate enough PESs may be obtained using the corresponding explicitly correlated versions (MP2-F12 or DCSD-F12) with a reduction in computational costs. Alternatively, computations revealed that SAPT(DFT) is as performant as CCSD(T)-F12/aug-cc-pVTZ, making it the method of choice for mapping the mD-PESs of COMs containing clusters. Therefore, we have used this approach to generate the 3D-PES of the benzonitrile-He complex along the intermonomer Jacobi coordinates. As an application, we have incorporated the analytic form of this PES into quantum dynamical computations to determine the cross sections of the rotational (de-)excitation of benzonitrile colliding with helium at a collision energy of 10 cm-1.
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Affiliation(s)
- Eya Derbali
- Laboratoire de Spectroscopie Atomique, Moléculaire et Applications LSAMA, Université de Tunis Al Manar, Tunis, Tunisia.
| | - Yosra Ajili
- Laboratoire de Spectroscopie Atomique, Moléculaire et Applications LSAMA, Université de Tunis Al Manar, Tunis, Tunisia.
| | - Bilel Mehnen
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadz Street 5, 87-100 Toruń, Poland
| | - Piotr S Żuchowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadz Street 5, 87-100 Toruń, Poland
| | - Dariusz Kędziera
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, ul. Gagarina 7, PL 87-100 Toruń, Poland.
| | - Muneerah Mogren Al-Mogren
- Department of Chemistry, College of Sciences, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Nejm-Edine Jaidane
- Laboratoire de Spectroscopie Atomique, Moléculaire et Applications LSAMA, Université de Tunis Al Manar, Tunis, Tunisia.
| | - Majdi Hochlaf
- Université Gustave Eiffel, COSYS/IMSE, 5 Bd Descartes 77454, Champs sur Marne, France.
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4
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Conte R, Nandi A, Qu C, Yu Q, Houston PL, Bowman JM. Semiclassical and VSCF/VCI Calculations of the Vibrational Energies of trans- and gauche-Ethanol Using a CCSD(T) Potential Energy Surface. J Phys Chem A 2022; 126:7709-7718. [PMID: 36240438 DOI: 10.1021/acs.jpca.2c06322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A recent full-dimensional Δ-Machine learning potential energy surface (PES) for ethanol is employed in semiclassical and vibrational self-consistent field (VSCF) and virtual-state configuration interaction (VCI) calculations, using MULTIMODE, to determine the anharmonic vibrational frequencies of vibration for both the trans and gauche conformers of ethanol. Both semiclassical and VSCF/VCI energies agree well with the experimental data. We find significant mixing between the VSCF basis states due to Fermi resonances between bending and stretching modes. The same effects are also accurately described by the full-dimensional semiclassical calculations. These are the first high-level anharmonic calculations using a PES, in particular a "gold-standard" CCSD(T) one.
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Affiliation(s)
- Riccardo Conte
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
| | - Apurba Nandi
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Chen Qu
- Independent Researcher, Toronto, Ontario M9B0E3, Canada
| | - Qi Yu
- Department of Chemistry Yale University, New Haven, Connecticut 06520, United States
| | - 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
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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5
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Bera PP, Noneman KK, Lee TJ. Energy Landscape and Structural and Spectroscopic Characterization of Diazirine and Its Cyclic Isomers. J Phys Chem A 2022; 126:4700-4708. [PMID: 35853204 DOI: 10.1021/acs.jpca.2c01444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Identifying new nitrogenated hydrocarbon molecules in the interstellar medium (ISM) is challenging because of the lack of comprehensive spectroscopic data from experiments. In this computational work, we focus on investigating the structures, relative energies, spectroscopic constants, and energy landscape of the cyclic isomers of diazirine (c-CH2N2) using ab initio quantum chemical methods. Density functional theory (DFT) methods and coupled cluster theory with singles and doubles including perturbative triples [CCSD(T)] and CCSD(T) with the explicitly correlated F12b correction [CCSD(T)-F12b] were employed for this purpose along with large correlation consistent cc-pVTZ, cc-pVQZ, and cc-pV5Z basis sets. Harmonic vibrational frequencies, infrared vibrational intensities, rotational constants, and dipole moments are reported. Anharmonic vibrational fundamentals along with centrifugal distortion constants, and vibration-rotation interaction constants are also reported for all the cyclic isomers. The energies computed with the CCSD(T) and CCSD(T)-F12b methods were extrapolated to the one-particle complete basis set (CBS) limit following a three-point formula. At the CCSD(T)-F12b/CBS level of theory, the 3,3H-diazirine (c-CH2N2) is the lowest energy cyclic isomer followed by 1,3H-diazirine, (E)-1,2H-diazirine, and (Z)-1,2H-diazirine, which are 20.1, 47.8, and 51.3 kcal mol-1 above the 3,3H-diazirine, respectively. Accurate structures and spectroscopic constants that are reported here could be useful for future identification of these cyclic nitrogenated organic molecules in the interstellar medium or circumstellar disks.
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Affiliation(s)
- Partha P Bera
- Bay Area Environmental Research Institute, Moffett Field, California 94035, United States
- Space Science and Astrobiology Division, NASA Ames Research Center, Mountain View, California 94035, United States
| | - Kendra K Noneman
- Space Science and Astrobiology Division, NASA Ames Research Center, Mountain View, California 94035, United States
- Micron School of Materials Science and Engineering, Boise State University, 1910 University Drive, Boise, Idaho 83725, United States
| | - Timothy J Lee
- Space Science and Astrobiology Division, NASA Ames Research Center, Mountain View, California 94035, United States
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6
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Carvalho JR, Vidal LN. Calculation of absolute Raman scattering cross-sections using vibrational self-consistent field/vibrational configuration interaction wave functions. J Comput Chem 2022; 43:1484-1494. [PMID: 35731622 DOI: 10.1002/jcc.26951] [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: 04/18/2022] [Revised: 05/21/2022] [Accepted: 06/02/2022] [Indexed: 11/12/2022]
Abstract
In the present study, the differential scattering cross-sections, depolarization ratios and Raman shifts of small molecular systems are obtained from configuration iteration wave functions of vibrational self-consistent field (VSCF) states. The transition polarizabilities were modeled using the Placzek approximation, neglecting those contributions not arising from the electric dipole mechanism. This theoretical approach is considered a good approximation for samples that absorb in the UV range if the excitation radiation falls in the visible region, as is the case of the molecules selected for the present study, namely: water, methane, and acetylene. Potential energy and electronic polarizability surfaces are calculated by the CCSD(T) and CC3 methods with aug-cc-p(C)V(T,Q,5)Z basis sets. The vibrational Hamiltonian includes the vibrational angular momentum contribution of the Watson kinetic energy operator. As expected, due to the variational nature of the VSCF and vibrational configuration interaction (VCI) methods, the Raman transition wavenumbers are substantially improved over the harmonic predictions. Surprisingly, the scattering cross-sections obtained using the harmonic approximation or the VSCF method better agrees with the experimental values than those cross-sections predicted using VCI wave functions. The more significant deviations of the VCI results from the experimental reference may be related to the significant uncertainties of the measured cross-sections. Still, it may also indicate that the VCI Raman transition moments may require a more accurate description of the electronic polarizability surface. Finally, the depolarization ratios calculated for H2 O and C2 D2 using harmonic and VCI wave functions have similar accuracy, whereas, for C2 H2 and C2 HD, the VCI results are more accurate.
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Affiliation(s)
- Jhonatas R Carvalho
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Luciano N Vidal
- Departamento Acadêmico de Química e Biologia, Universidade Tecnológica Federal do Paraná, Curitiba, Paraná, Brazil
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7
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Töpfer K, Upadhyay M, Meuwly M. Quantitative molecular simulations. Phys Chem Chem Phys 2022; 24:12767-12786. [PMID: 35593769 PMCID: PMC9158373 DOI: 10.1039/d2cp01211a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 04/30/2022] [Indexed: 11/21/2022]
Abstract
All-atom simulations can provide molecular-level insights into the dynamics of gas-phase, condensed-phase and surface processes. One important requirement is a sufficiently realistic and detailed description of the underlying intermolecular interactions. The present perspective provides an overview of the present status of quantitative atomistic simulations from colleagues' and our own efforts for gas- and solution-phase processes and for the dynamics on surfaces. Particular attention is paid to direct comparison with experiment. An outlook discusses present challenges and future extensions to bring such dynamics simulations even closer to reality.
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Affiliation(s)
- Kai Töpfer
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
| | - Meenu Upadhyay
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
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8
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Cheng J, Wang J, Tan Z, Wu S. Theoretical Study of Photoassociation of Alkali-Metal Dimers. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024421150061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Westermayr J, Marquetand P. Machine Learning for Electronically Excited States of Molecules. Chem Rev 2021; 121:9873-9926. [PMID: 33211478 PMCID: PMC8391943 DOI: 10.1021/acs.chemrev.0c00749] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Indexed: 12/11/2022]
Abstract
Electronically excited states of molecules are at the heart of photochemistry, photophysics, as well as photobiology and also play a role in material science. Their theoretical description requires highly accurate quantum chemical calculations, which are computationally expensive. In this review, we focus on not only how machine learning is employed to speed up such excited-state simulations but also how this branch of artificial intelligence can be used to advance this exciting research field in all its aspects. Discussed applications of machine learning for excited states include excited-state dynamics simulations, static calculations of absorption spectra, as well as many others. In order to put these studies into context, we discuss the promises and pitfalls of the involved machine learning techniques. Since the latter are mostly based on quantum chemistry calculations, we also provide a short introduction into excited-state electronic structure methods and approaches for nonadiabatic dynamics simulations and describe tricks and problems when using them in machine learning for excited states of molecules.
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Affiliation(s)
- Julia Westermayr
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
| | - Philipp Marquetand
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
- Vienna
Research Platform on Accelerating Photoreaction Discovery, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
- Data
Science @ Uni Vienna, University of Vienna, Währinger Strasse 29, 1090 Vienna, Austria
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10
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Abstract
Electronically excited states of molecules are at the heart of photochemistry, photophysics, as well as photobiology and also play a role in material science. Their theoretical description requires highly accurate quantum chemical calculations, which are computationally expensive. In this review, we focus on not only how machine learning is employed to speed up such excited-state simulations but also how this branch of artificial intelligence can be used to advance this exciting research field in all its aspects. Discussed applications of machine learning for excited states include excited-state dynamics simulations, static calculations of absorption spectra, as well as many others. In order to put these studies into context, we discuss the promises and pitfalls of the involved machine learning techniques. Since the latter are mostly based on quantum chemistry calculations, we also provide a short introduction into excited-state electronic structure methods and approaches for nonadiabatic dynamics simulations and describe tricks and problems when using them in machine learning for excited states of molecules.
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Affiliation(s)
- Julia Westermayr
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
| | - Philipp Marquetand
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
- Vienna Research Platform on Accelerating Photoreaction Discovery, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
- Data Science @ Uni Vienna, University of Vienna, Währinger Strasse 29, 1090 Vienna, Austria
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11
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Mendolicchio M, Bloino J, Barone V. General Perturb-Then-Diagonalize Model for the Vibrational Frequencies and Intensities of Molecules Belonging to Abelian and Non-Abelian Symmetry Groups. J Chem Theory Comput 2021; 17:4332-4358. [PMID: 34085530 PMCID: PMC8280743 DOI: 10.1021/acs.jctc.1c00240] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Indexed: 11/29/2022]
Abstract
In this paper, we show that the standard second-order vibrational perturbation theory (VPT2) for Abelian groups can be used also for non-Abelian groups without employing specific equations for two- or threefold degenerate vibrations but rather handling in the proper way all the degeneracy issues and deriving the peculiar spectroscopic signatures of non-Abelian groups (e.g., l -doubling) by a posteriori transformations of the eigenfunctions. Comparison with the results of previous conventional implementations shows a perfect agreement for the vibrational energies of linear and symmetric tops, thus paving the route to the transparent extension of the equations already available for asymmetric tops to the energies of spherical tops and the infrared and Raman intensities of molecules belonging to non-Abelian symmetry groups. The whole procedure has been implemented in our general engine for vibro-rotational computations beyond the rigid rotor/harmonic oscillator model and has been validated on a number of test cases.
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Affiliation(s)
| | - Julien Bloino
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
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12
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Qu C, Houston PL, Conte R, Nandi A, Bowman JM. MULTIMODE Calculations of Vibrational Spectroscopy and 1d Interconformer Tunneling Dynamics in Glycine Using a Full-Dimensional Potential Energy Surface. J Phys Chem A 2021; 125:5346-5354. [PMID: 34110169 DOI: 10.1021/acs.jpca.1c03738] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A full-dimensional, permutationally invariant polynomial potential energy surface for glycine recently reported (R. Conte et al., J. Chem. Phys. 2020, 153, 244301) is used with the code MULTIMODE to determine the IR absorption spectra for Conformers I and II using a new separable dipole moment function. The calculated spectra agree well with the experimental ones. The full-dimensional nature of the potential allows us also to examine dynamical results, such as tunneling rates. Remarkably, using a one-dimensional path based on the potential energy surface to estimate the tunneling rate from Conformer VI to Conformer I, good agreement is found with the recent experimental measurement. Finally a brief comparison of our potential energy surface with a recently reported sGDML one is made.
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Affiliation(s)
- Chen Qu
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - 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
| | - Riccardo Conte
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
| | - Apurba Nandi
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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13
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Dinu DF, Podewitz M, Grothe H, Loerting T, Liedl KR. On the synergy of matrix-isolation infrared spectroscopy and vibrational configuration interaction computations. Theor Chem Acc 2020; 139:174. [PMID: 33192169 PMCID: PMC7652801 DOI: 10.1007/s00214-020-02682-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 10/05/2020] [Indexed: 11/08/2022]
Abstract
The key feature of matrix-isolation infrared (MI-IR) spectroscopy is the isolation of single guest molecules in a host system at cryogenic conditions. The matrix mostly hinders rotation of the guest molecule, providing access to pure vibrational features. Vibrational self-consistent field (VSCF) and configuration interaction computations (VCI) on ab initio multimode potential energy surfaces (PES) give rise to anharmonic vibrational spectra. In a single-sourced combination of these experimental and computational approaches, we have established an iterative spectroscopic characterization procedure. The present article reviews the scope of this procedure by highlighting the strengths and limitations based on the examples of water, carbon dioxide, methane, methanol, and fluoroethane. An assessment of setups for the construction of the multimode PES on the example of methanol demonstrates that CCSD(T)-F12 level of theory is preferable to compute (a) accurate vibrational frequencies and (b) equilibrium or vibrationally averaged structural parameters. Our procedure has allowed us to uniquely assign unknown or disputed bands and enabled us to clarify problematic spectral regions that are crowded with combination bands and overtones. Besides spectroscopic assignment, the excellent agreement between theory and experiment paves the way to tackle questions of rather fundamental nature as to whether or not matrix effects are systematic, and it shows the limits of conventional notations used by spectroscopists.
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Affiliation(s)
- Dennis F Dinu
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria.,Institute of Material Chemistry, TU Vienna, Vienna, Austria.,Institute of Physical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Maren Podewitz
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Hinrich Grothe
- Institute of Material Chemistry, TU Vienna, Vienna, Austria
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
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14
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Dral PO, Owens A, Dral A, Csányi G. Hierarchical machine learning of potential energy surfaces. J Chem Phys 2020; 152:204110. [DOI: 10.1063/5.0006498] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Pavlo O. Dral
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Alec Owens
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Alexey Dral
- BigData Team, 1A Tormoznoye Shosse Off 17, Yaroslavl, Yaroslavl 150022, Russian Federation
| | - Gábor Csányi
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
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15
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Westermayr J, Faber FA, Christensen AS, von Lilienfeld OA, Marquetand P. Neural networks and kernel ridge regression for excited states dynamics of CH2NH$_2^+$: From single-state to multi-state representations and multi-property machine learning models. MACHINE LEARNING-SCIENCE AND TECHNOLOGY 2020. [DOI: 10.1088/2632-2153/ab88d0] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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16
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DFT meets the segmented polarization consistent basis sets: Performances in the computation of molecular structures, rotational and vibrational spectroscopic properties. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.127886] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Boussessi R, Tasinato N, Pietropolli Charmet A, Stoppa P, Barone V. Sextic centrifugal distortion constants: interplay of density functional and basis set for accurate yet feasible computations. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1734678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | | | | | - Paolo Stoppa
- Università Ca’ Foscari Venezia, Dipartimento di Scienze Molecolari e Nanosistemi, Mestre Venezia, Italy
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18
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Dinu DF, Podewitz M, Grothe H, Loerting T, Liedl KR. Decomposing anharmonicity and mode-coupling from matrix effects in the IR spectra of matrix-isolated carbon dioxide and methane. Phys Chem Chem Phys 2020; 22:17932-17947. [DOI: 10.1039/d0cp02121k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combined experimental and computational approach revealed similarities and differences in the vibrational signature of matrix-isolated carbon dioxide and methane.
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Affiliation(s)
- Dennis F. Dinu
- Institute of General
- Inorganic and Theoretical Chemistry
- University of Innsbruck
- A-6020 Innsbruck
- Austria
| | - Maren Podewitz
- Institute of General
- Inorganic and Theoretical Chemistry
- University of Innsbruck
- A-6020 Innsbruck
- Austria
| | - Hinrich Grothe
- Institute of Materials Chemistry
- TU Wien
- A-1060 Vienna
- Austria
| | - Thomas Loerting
- Institute of Physical Chemistry
- University of Innsbruck
- A-6020 Innsbruck
- Austria
| | - Klaus R. Liedl
- Institute of General
- Inorganic and Theoretical Chemistry
- University of Innsbruck
- A-6020 Innsbruck
- Austria
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19
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McKemmish LK, Tennyson J. General mathematical formulation of scattering processes in atom-diatomic collisions in the RmatReact methodology. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180409. [PMID: 31378187 PMCID: PMC6710894 DOI: 10.1098/rsta.2018.0409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/26/2019] [Indexed: 06/10/2023]
Abstract
Accurately modelling cold and ultracold reactive collisions occurring over deep potential wells, such as [Formula: see text], requires the development of new theoretical and computational methodologies. One potentially useful framework is the R-matrix method adopted widely for electron-molecule collisions which has more recently been applied to non-reactive heavy-particle collisions such as Ar-Ar. The existing treatment of non-reactive elastic and inelastic scattering needs to be substantially extended to enable modelling of reactive collisions: this is the subject of this paper. Herein, we develop the general mathematical formulation for non-reactive elastic and inelastic scattering, photoassociation, photodissociation, charge exchange and reactive scattering using the R-matrix method. Of particular note is that the inner region, of central importance to calculable R-matrix methodologies, must be finite in all scattering coordinates rather than a single scattering coordinate as for non-reactive scattering. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- Laura K. McKemmish
- School of Chemistry, University of New South Wales, Kensington, Sydney, NSW 2052, Australia
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
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20
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Prosmiti R, Valdés Á. The smallest proton-bound dimer H 5+: theoretical progress. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180396. [PMID: 31378176 PMCID: PMC6710890 DOI: 10.1098/rsta.2018.0396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/19/2019] [Indexed: 06/10/2023]
Abstract
The protonated hydrogen dimer, H5+, is the smallest system including proton transfer, and has been of long-standing interest since its first laboratory observation in 1962. H5+ and its isotopologues are the intermediate complexes in deuterium fractionation reactions, and are of central importance in molecular astrophysics. The recently recorded infrared spectra of both H5+ and D5+ reveal a rich vibrational dynamics of the cations, which presents a challenge for standard theoretical approaches. Although H5+ is a four-electron ion, which makes highly accurate electronic structure calculations tractable, the construction of ab initio-based potential energy and dipole moment surfaces has proved a hard task. In the same vein, the difficulties in treating the nuclear motion could also become cumbersome due to their high dimensionality, floppiness and/or symmetry. These systems are prototypical examples for studying large-amplitude motions, as they are highly delocalized, interconverting between equivalent minima through internal rotation and proton transfer motions requiring state-of-the-art treatments. Recent advances in the computational vibrational spectroscopy of the H5+ cation and its isotopologues are reported from full quantum spectral simulations, providing important information in a rigorous manner, and open perspectives for further future investigations. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- Rita Prosmiti
- Departamento PAMS, Instituto de Física Fundamental (IFF-CSIC), CSIC, Serrano 123, 28006 Madrid, Spain
| | - Álvaro Valdés
- Departamento de Física, Universidad Nacional de Colombia, Calle 26, Cra 39, Edificio 404, Bogotá, Colombia
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21
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Markus CR, McCall BJ. Highly accurate experimentally determined energy levels of H 3. J Chem Phys 2019; 150:214303. [PMID: 31176322 DOI: 10.1063/1.5099454] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A sub-Doppler rovibrational spectroscopic survey of H3 + has been conducted which included 36 transitions in the ν2 ← 0 fundamental band, 15 transitions in the 2ν2 2←ν2 hot band, and 7 transitions in the 2ν2 2←0 overtone band, improving the uncertainties of most transitions by more than an order of magnitude to ∼4 MHz. Combination differences were used to determine relative energy levels and forbidden rotational transitions up to J = 6. A fit of the ground state to an effective Hamiltonian was used to connect ortho and para states, and to determine the absolute energy levels relative to the forbidden (0, 0) state. Ultimately, 62 rovibrational energy levels in the ground, ν2, and 2ν2 2 states were determined with ∼10 MHz uncertainty. Comparing the experimentally determined energy levels with ab initio calculations revealed an unexpected dependence of the residuals on the quantum number G.
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Affiliation(s)
- Charles R Markus
- Department of Chemistry, University of Illinois, 600 South Mathews Ave., Urbana, Illinois 61801, USA
| | - Benjamin J McCall
- Department of Chemistry, University of Illinois, 600 South Mathews Ave., Urbana, Illinois 61801, USA
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22
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Owens A, Yurchenko SN. Theoretical rotation-vibration spectroscopy of cis- and trans-diphosphene (P 2H 2) and the deuterated species P 2HD. J Chem Phys 2019; 150:194308. [PMID: 31117776 DOI: 10.1063/1.5092767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Growing astronomical interest in phosphorous (P) chemistry is stimulating the search for new interstellar P-bearing molecules, a task requiring detailed knowledge of the microwave and infrared molecular spectrum. In this work, we present comprehensive rotation-vibration line lists of the cis- and trans-isomers of diphosphene (P2H2). The line lists have been generated using robust, first-principles methodologies based on newly computed, high-level ab initio potential energy and dipole moment surfaces. Transitions are considered between states with energies up to 8000 cm-1 and total angular momentum J ≤ 25. These are the first-ever line lists to be reported for P2H2, and they should significantly facilitate future spectroscopic characterization of this system. The deuterated species trans-P2HD and the effect of its dynamic dipole moment on the rovibrational spectrum are also discussed.
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Affiliation(s)
- Alec Owens
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Sergei N Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
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23
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Krasnoshchekov SV, Chang X. Ladder operators for Morse oscillator and a perturbed vibrational problem. INT REV PHYS CHEM 2019. [DOI: 10.1080/0144235x.2019.1593583] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | - Xuanhao Chang
- School of Nuclear Science and Engineering, Tomsk Polytechnic University, Tomsk, Russia
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24
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Martin-Drumel MA, Baraban JH, Changala PB, Stanton JF, McCarthy MC. The Hunt for Elusive Molecules: Insights from Joint Theoretical and Experimental Investigations. Chemistry 2019; 25:7243-7258. [PMID: 30673130 DOI: 10.1002/chem.201805986] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 11/10/2022]
Abstract
Rotational spectroscopy is an invaluable tool to unambiguously determine the molecular structure of a species, and sometimes even to establish its very existence. This article illustrates how experimental and theoretical state-of-the-art tools can be used in tandem to investigate the rotational structure of molecules, with particular emphasis on those that have long remained elusive. The examples of three emblematic species-gauche-butadiene, disilicon carbide, and germanium dicarbide-highlight the close, mutually beneficial interaction between high-level theoretical calculations and sensitive microwave measurements. Prospects to detect other elusive molecules of chemical and astronomical interest are discussed.
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Affiliation(s)
- Marie-Aline Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405, Orsay, France
| | - Joshua H Baraban
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - P Bryan Changala
- JILA, National Institute of Standards and Technology and Department of, Physics, University of Colorado, Boulder, CO, 80309, USA
| | - John F Stanton
- Quantum Theory Project, Departments of Chemistry and Physics, Univ. of Florida, Gainesville, FL, 32611, USA
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, 02138, USA
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25
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Qu C, Bowman JM. Quantum approaches to vibrational dynamics and spectroscopy: is ease of interpretation sacrificed as rigor increases? Phys Chem Chem Phys 2019; 21:3397-3413. [DOI: 10.1039/c8cp04990d] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The subject of this Perspective is quantum approaches, beyond the harmonic approximation, to vibrational dynamics and IR spectroscopy.
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Affiliation(s)
- Chen Qu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University
- Atlanta
- USA
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University
- Atlanta
- USA
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26
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Owens A, Yachmenev A, Küpper J, Yurchenko SN, Thiel W. The rotation–vibration spectrum of methyl fluoride from first principles. Phys Chem Chem Phys 2019; 21:3496-3505. [DOI: 10.1039/c8cp01721b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
State-of-the-art theoretical methods are used to investigate the rotation–vibration spectrum of methyl fluoride.
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Affiliation(s)
- Alec Owens
- Center for Free-Electron Laser Science (CFEL)
- Deutsches Elektronen-Synchrotron DESY
- 22607 Hamburg
- Germany
- The Hamburg Center for Ultrafast Imaging
| | - Andrey Yachmenev
- Center for Free-Electron Laser Science (CFEL)
- Deutsches Elektronen-Synchrotron DESY
- 22607 Hamburg
- Germany
- The Hamburg Center for Ultrafast Imaging
| | - Jochen Küpper
- Center for Free-Electron Laser Science (CFEL)
- Deutsches Elektronen-Synchrotron DESY
- 22607 Hamburg
- Germany
- The Hamburg Center for Ultrafast Imaging
| | - Sergei N. Yurchenko
- Department of Physics and Astronomy
- University College London
- WC1E 6BT London
- UK
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung
- 45470 Mülheim an der Ruhr
- Germany
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27
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Mátyus E. Non-adiabatic mass correction to the rovibrational states of molecules: Numerical application for the H 2 + molecular ion. J Chem Phys 2018; 149:194111. [PMID: 30466265 DOI: 10.1063/1.5050401] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
General transformation expressions of the second-order non-adiabatic Hamiltonian of the atomic nuclei, including the kinetic-energy correction terms, are derived upon the change from laboratory-fixed Cartesian coordinates to general curvilinear coordinate systems commonly used in rovibrational computations. The kinetic-energy or so-called "mass-correction" tensor elements are computed with the stochastic variational method and floating explicitly correlated Gaussian functions for the H 2 + molecular ion in its ground electronic state. {Further numerical applications for the 4 He 2 + molecular ion are presented in the forthcoming paper, Paper II [E. Mátyus, J. Chem. Phys. 149, 194112 (2018)]}. The general, curvilinear non-adiabatic kinetic energy operator expressions are used in the examples, and non-adiabatic rovibrational energies and corrections are determined by solving the rovibrational Schrödinger equation including the diagonal Born-Oppenheimer as well as the mass-tensor corrections.
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Affiliation(s)
- Edit Mátyus
- Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
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28
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Dickerson CE, Bera PP, Lee TJ. Characterization of Azirine and Its Structural Isomers. J Phys Chem A 2018; 122:8898-8904. [PMID: 30350988 DOI: 10.1021/acs.jpca.8b07788] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structures and spectroscopic properties of azirine (C2H3N), a nitrogen-containing three-membered cyclic molecule, and its isomers were studied with state-of-the-art ab initio quantum chemical methods. Azirine is isomeric with methyl cyanide (CH3CN) and methyl isocyanide (CH3NC)-both observed in the star-forming regions of Sgr B2. In this study, we characterize the stationary points on the potential energy surface, relative energies, dipole moments, rotational constants, and harmonic vibrational frequencies of the 2 H-azirine ( a), 1 H-2,2 H-azirine ( b, carbene isomer), and 1 H-azirine ( c) cyclic isomers. The CCSD(T) method and density functional theory (DFT), using the ωB97-X functional, along with Dunning's cc-pVXZ (X = T and Q) basis sets were used to optimize molecular geometries and calculate vibrational frequencies. The 2 H-azirine, an imine isomer ( a), was found to be the lowest in energy among the cyclic isomers, followed by the carbene isomer ( b), and last the 1 H-azirine, an enamine isomer ( c). All three cyclic isomers have a C s symmetry equilibrium structure. Azirines, if identified (three linear C2H3N isomers are already identified in the same source toward the galactic center, Sgr B2), would be the first nitrogen-containing cyclic molecules identified in an astronomical observation.
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Affiliation(s)
| | - Partha P Bera
- Space Science and Astrobiology Division , NASA Ames Research Center , Mountain View , California 94035 , United States.,Bay Area Environmental Research Institute , Moffett Field , California 94035 , United States
| | - Timothy J Lee
- Space Science and Astrobiology Division , NASA Ames Research Center , Mountain View , California 94035 , United States
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29
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Affiliation(s)
- Edit Mátyus
- Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
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30
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Lischka H, Nachtigallová D, Aquino AJA, Szalay PG, Plasser F, Machado FBC, Barbatti M. Multireference Approaches for Excited States of Molecules. Chem Rev 2018; 118:7293-7361. [DOI: 10.1021/acs.chemrev.8b00244] [Citation(s) in RCA: 197] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hans Lischka
- School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, P.R. China
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
| | - Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry v.v.i., The Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, 78371 Olomouc, Czech Republic
| | - Adélia J. A. Aquino
- School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, P.R. China
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
- Institute for Soil Research, University of Natural Resources and Life Sciences Vienna, Peter-Jordan-Strasse 82, A-1190 Vienna, Austria
| | - Péter G. Szalay
- ELTE Eötvös Loránd University, Laboratory of Theoretical Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
| | - Felix Plasser
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
- Department of Chemistry, Loughborough University, Leicestershire LE11 3TU, United Kingdom
| | - Francisco B. C. Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 12228-900, São Paulo, Brazil
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31
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Manzhos S, Wang X, Carrington T. A multimode-like scheme for selecting the centers of Gaussian basis functions when computing vibrational spectra. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2017.10.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Jaquet R, Khoma MV. Investigation of non-adiabatic effects for the ro-vibrational spectrum of H3+: the use of a single potential energy surface with geometry-dependent nuclear masses. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1464225] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Ralph Jaquet
- Theoretische Chemie, Universität Siegen , Siegen, Germany
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33
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Qu C, Bowman J. Quantum and classical IR spectra of (HCOOH)2, (DCOOH)2 and (DCOOD)2 using ab initio potential energy and dipole moment surfaces. Faraday Discuss 2018; 212:33-49. [DOI: 10.1039/c8fd00077h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Full-dimensional (24 modes) quantum calculation of the IR spectrum of (DCOOD)2, and comparison with classical MD one.
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Affiliation(s)
- Chen Qu
- Department of Chemistry
- Cherry L. Emerson Center for Scientific Computations
- Emory University
- Atlanta
- USA
| | - Joel M. Bowman
- Department of Chemistry
- Cherry L. Emerson Center for Scientific Computations
- Emory University
- Atlanta
- USA
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34
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Buchowiecki M, Prątnicki F. High temperature partition function – a key role of ro-vibrational coupling and inflection points. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1334132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Marcin Buchowiecki
- Institute of Physics, Department of Mathematics and Physics, University of Szczecin, Szczecin, Poland
| | - Filip Prątnicki
- Institute of Physics, Department of Mathematics and Physics, University of Szczecin, Szczecin, Poland
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35
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Fleisher AJ, Long DA, Liu Q, Gameson L, Hodges JT. Optical Measurement of Radiocarbon below Unity Fraction Modern by Linear Absorption Spectroscopy. J Phys Chem Lett 2017; 8:4550-4556. [PMID: 28880564 PMCID: PMC5725230 DOI: 10.1021/acs.jpclett.7b02105] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
High-precision measurements of radiocarbon (14C) near or below a fraction modern 14C of 1 (F14C ≤ 1) are challenging and costly. An accurate, ultrasensitive linear absorption approach to detecting 14C would provide a simple and robust benchtop alternative to off-site accelerator mass spectrometry facilities. Here we report the quantitative measurement of 14C in gas-phase samples of CO2 with F14C < 1 using cavity ring-down spectroscopy in the linear absorption regime. Repeated analysis of CO2 derived from the combustion of either biogenic or petrogenic sources revealed a robust ability to differentiate samples with F14C < 1. With a combined uncertainty of 14C/12C = 130 fmol/mol (F14C = 0.11), initial performance of the calibration-free instrument is sufficient to investigate a variety of applications in radiocarbon measurement science including the study of biofuels and bioplastics, illicitly traded specimens, bomb dating, and atmospheric transport.
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36
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Jaquet R, Khoma MV. Investigation of Nonadiabatic Effects for the Vibrational Spectrum of a Triatomic Molecule: The Use of a Single Potential Energy Surface with Distance-Dependent Masses for H 3. J Phys Chem A 2017; 121:7016-7030. [PMID: 28820589 DOI: 10.1021/acs.jpca.7b04703] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
On the basis of first-principles, the influence of nonadiabatic effects on the vibrational bound states of H3+ has been investigated using distance-dependent reduced masses and only one single potential energy surface. For these new vibrational calculations, potentials based on explicitly correlated wave functions are used where, in addition, adiabatic corrections and relativistic contributions are taken into account. For the first time, several different fully distance-dependent reduced mass surfaces in three dimensions have been incorporated in the vibrational calculations.
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Affiliation(s)
- Ralph Jaquet
- Theoretische Chemie, Universität Siegen , D-57068 Siegen, Germany
| | - Mykhaylo V Khoma
- Theoretische Chemie, Universität Siegen , D-57068 Siegen, Germany
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37
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Yu HG, Song H, Yang M. A rigorous full-dimensional quantum dynamics study of tunneling splitting of rovibrational states of vinyl radical C2H3. J Chem Phys 2017; 146:224307. [DOI: 10.1063/1.4985183] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hua-Gen Yu
- Division of Chemistry, Department of Energy and Photon Sciences, Brookhaven National Laboratory, Upton, New York 11793-5000, USA
| | - Hongwei Song
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
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38
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Szidarovszky T, Yamanouchi K. Full-dimensional simulation of the laser-induced alignment dynamics of H2He+. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1297863] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Tamás Szidarovszky
- Department of Chemistry, School of Science, The University of Tokyo , Tokyo, Japan
| | - Kaoru Yamanouchi
- Department of Chemistry, School of Science, The University of Tokyo , Tokyo, Japan
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39
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Hochlaf M. Advances in spectroscopy and dynamics of small and medium sized molecules and clusters. Phys Chem Chem Phys 2017; 19:21236-21261. [DOI: 10.1039/c7cp01980g] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Investigations of the spectroscopy and dynamics of small- and medium-sized molecules and clusters represent a hot topic in atmospheric chemistry, biology, physics, atto- and femto-chemistry and astrophysics.
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Affiliation(s)
- Majdi Hochlaf
- Université Paris-Est
- Laboratoire Modélisation et Simulation Multi Echelle
- MSME UMR 8208 CNRS
- 77454 Marne-la-Vallée
- France
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40
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Tew DP, Mizukami W. Ab Initio Vibrational Spectroscopy of cis- and trans-Formic Acid from a Global Potential Energy Surface. J Phys Chem A 2016; 120:9815-9828. [DOI: 10.1021/acs.jpca.6b09952] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David P. Tew
- School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Wataru Mizukami
- School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
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