1
|
Barone V, Di Grande S, Puzzarini C. Toward Accurate yet Effective Computations of Rotational Spectroscopy Parameters for Biomolecule Building Blocks. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020913. [PMID: 36677970 PMCID: PMC9863398 DOI: 10.3390/molecules28020913] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/01/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023]
Abstract
The interplay of high-resolution rotational spectroscopy and quantum-chemical computations plays an invaluable role in the investigation of biomolecule building blocks in the gas phase. However, quantum-chemical methods suffer from unfavorable scaling with the dimension of the system under consideration. While a complete characterization of flexible systems requires an elaborate multi-step strategy, in this work, we demonstrate that the accuracy obtained by quantum-chemical composite approaches in the prediction of rotational spectroscopy parameters can be approached by a model based on density functional theory. Glycine and serine are employed to demonstrate that, despite its limited cost, such a model is able to predict rotational constants with an accuracy of 0.3% or better, thus paving the way toward the accurate characterization of larger flexible building blocks of biomolecules.
Collapse
Affiliation(s)
- Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-50126 Pisa, Italy
- Correspondence: (V.B.); (C.P.)
| | - Silvia Di Grande
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-50126 Pisa, Italy
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
| | - Cristina Puzzarini
- Rotational and Computational Spectroscopy Lab, Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via F. Selmi 2, I-40126 Bologna, Italy
- Correspondence: (V.B.); (C.P.)
| |
Collapse
|
2
|
Xie C, Guan Y, Yarkony DR, Guo H. Vibrational energy levels of the S0 and S1 states of formaldehyde using an accurate ab initio based global diabatic potential energy matrix. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1918775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Changjian Xie
- Institute of Modern Physics, Northwest University, Xi’an, Shaanxi, People’s Republic of China
| | - Yafu Guan
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - David R. Yarkony
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM, USA
| |
Collapse
|
3
|
Abstract
Linear molecules usually represent a special case in rotational-vibrational calculations due to a singularity of the kinetic energy operator that arises from the rotation about the a (the principal axis of least moment of inertia, becoming the molecular axis at the linear equilibrium geometry) being undefined. Assuming the standard ro-vibrational basis functions, in the 3N−6 approach, of the form ∣ν1,ν2,ν3ℓ3;J,k,m⟩, tackling the unique difficulties of linear molecules involves constraining the vibrational and rotational functions with k=ℓ3, which are the projections, in units of ℏ, of the corresponding angular momenta onto the molecular axis. These basis functions are assigned to irreducible representations (irreps) of the C2v(M) molecular symmetry group. This, in turn, necessitates purpose-built codes that specifically deal with linear molecules. In the present work, we describe an alternative scheme and introduce an (artificial) group that ensures that the condition ℓ3=k is automatically applied solely through symmetry group algebra. The advantage of such an approach is that the application of symmetry group algebra in ro-vibrational calculations is ubiquitous, and so this method can be used to enable ro-vibrational calculations of linear molecules in polyatomic codes with fairly minimal modifications. To this end, we construct a—formally infinite—artificial molecular symmetry group D∞h(AEM), which consists of one-dimensional (non-degenerate) irreducible representations and use it to classify vibrational and rotational basis functions according to ℓ and k. This extension to non-rigorous, artificial symmetry groups is based on cyclic groups of prime-order. Opposite to the usual scenario, where the form of symmetry adapted basis sets is dictated by the symmetry group the molecule belongs to, here the symmetry group D∞h(AEM) is built to satisfy properties for the convenience of the basis set construction and matrix elements calculations. We believe that the idea of purpose-built artificial symmetry groups can be useful in other applications.
Collapse
|
4
|
Nejad A, Crittenden DL. On the separability of large-amplitude motions in anharmonic frequency calculations. Phys Chem Chem Phys 2020; 22:20588-20601. [PMID: 32966420 DOI: 10.1039/d0cp03515g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nuclear vibrational theories based upon the Watson Hamiltonian are ubiquitous in quantum chemistry, but are generally unable to model systems in which the wavefunction can delocalise over multiple energy minima, i.e. molecules that have low-energy torsion and inversion barriers. In a 2019 Chemical Reviews article, Puzzarini et al. note that a common workaround is to simply decouple these problematic modes from all other vibrations in the system during anharmonic frequency calculations. They also point out that this approximation can be "ill-suited", but do not quantify the errors introduced. In this work, we present the first systematic investigation into how separating out or constraining torsion and inversion vibrations within potential energy surface (PES) expansions affects the accuracy of computed fundamental wavenumbers for the remaining vibrational modes, using a test set of 19 tetratomic molecules for which high quality analytic potential energy surfaces and fully-coupled anharmonic reference fundamental frequencies are available. We find that the most effective and efficient strategy is to remove the mode in question from the PES expansion entirely. This introduces errors of up to +10 cm-1 in stretching fundamentals that would otherwise couple to the dropped mode, and ±5 cm-1 in all other fundamentals. These errors are approximately commensurate with, but not necessarily additional to, errors due to the choice of electronic structure model used in constructing spectroscopically accurate PES.
Collapse
Affiliation(s)
- Arman Nejad
- Institute of Physical Chemistry, University of Göttingen, Tammannstr. 6, D-37077 Göttingen, Germany.
| | - Deborah L Crittenden
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| |
Collapse
|
5
|
Maergoiz AI, Troe J, Ushakov V. Simplified Representation of Multichannel Thermal Unimolecular Reactions. II. Refined Parametrization of Formaldehyde Dissociation. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2019-1580] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Simplified representations of branching fractions for thermal unimolecular two-channel reactions are discussed. The dissociation of formaldehyde serves as an illustrative example. Quantum-corrected classical trajectory calculations on an ab initio potential energy surface are combined with master equation calculations for collisional energy transfer. The treatment accounts for roaming atom dynamics. The dependence of the channel branching fractions on the bath gas pressure and temperature, on the collision efficiencies, and on the difference of channel threshold energies, are explored. It is discussed to what extent the derived simplified representations of channel branching fractions can be generalized.
Collapse
Affiliation(s)
- Anatoli I. Maergoiz
- Max-Planck-Institut für Biophysikalische Chemie , Am Fassberg 11 , D-37077 Göttingen , Germany
| | - Jürgen Troe
- Max-Planck-Institut für Biophysikalische Chemie , Am Fassberg 11 , D-37077 Göttingen , Germany
- Institut für Physikalische Chemie, Universität Göttingen , Tammannstrasse 6 , D-37077 Göttingen , Germany
| | - Vladimir Ushakov
- Institute of Problems of Chemical Physics , Russian Academy of Sciences , 142432 Chernogolovka , Russia
| |
Collapse
|
6
|
Rey M. Group-theoretical formulation of an Eckart-frame kinetic energy operator in curvilinear coordinates for polyatomic molecules. J Chem Phys 2019; 151:024101. [DOI: 10.1063/1.5109482] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael Rey
- Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, F-51687 Reims Cedex 2, France
| |
Collapse
|
7
|
Transformation Properties under the Operations of
the Molecular Symmetry Groups G36 and G36(EM) of
Ethane H3CCH3. Symmetry (Basel) 2019. [DOI: 10.3390/sym11070862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In the present work, we report a detailed description of the symmetry propertiesof the eight-atomic molecule ethane, with the aim of facilitating the variational calculations ofrotation-vibration spectra of ethane and related molecules. Ethane consists of two methyl groupsCH3 where the internal rotation (torsion) of one CH3 group relative to the other is of large amplitudeand involves tunnelling between multiple minima of the potential energy function. The molecularsymmetry group of ethane is the 36-element group G36, but the construction of symmetrised basisfunctions is most conveniently done in terms of the 72-element extended molecular symmetrygroup G36(EM). This group can subsequently be used in the construction of block-diagonal matrixrepresentations of the ro-vibrational Hamiltonian for ethane. The derived transformation matricesassociated with G36(EM) have been implemented in the variational nuclear motion program TROVE(Theoretical ROVibrational Energies). TROVE variational calculations are used as a practical exampleof a G36(EM) symmetry adaptation for large systems with a non-rigid, torsional degree of freedom.We present the derivation of irreducible transformation matrices for all 36 (72) operations of G36(M)(G36(EM)) and also describe algorithms for a numerical construction of these matrices based on aset of four (five) generators. The methodology presented is illustrated on the construction of thesymmetry-adapted representations both of the potential energy function of ethane and of the rotation,torsion and vibration basis set functions.
Collapse
|
8
|
Abbott AS, Turney JM, Zhang B, Smith DGA, Altarawy D, Schaefer HF. PES-Learn: An Open-Source Software Package for the Automated Generation of Machine Learning Models of Molecular Potential Energy Surfaces. J Chem Theory Comput 2019; 15:4386-4398. [DOI: 10.1021/acs.jctc.9b00312] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Adam S. Abbott
- Center for Computational Quantum Chemistry, The University of Georgia, Athens, Georgia 30602, United States
| | - Justin M. Turney
- Center for Computational Quantum Chemistry, The University of Georgia, Athens, Georgia 30602, United States
| | - Boyi Zhang
- Center for Computational Quantum Chemistry, The University of Georgia, Athens, Georgia 30602, United States
| | - Daniel G. A. Smith
- Molecular Sciences Software Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Doaa Altarawy
- Molecular Sciences Software Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
- Computer and Systems Engineering Department, Alexandria University, Alexandria, Egypt
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, The University of Georgia, Athens, Georgia 30602, United States
| |
Collapse
|
9
|
Lee VGM, Madison LR, McCoy AB. Evaluation of Matrix Elements Using Diffusion Monte Carlo Wave Functions. J Phys Chem A 2019; 123:4370-4378. [DOI: 10.1021/acs.jpca.8b11213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Victor G. M. Lee
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Lindsey R. Madison
- Department of Chemistry, Colby College, Waterville, Maine 04901, United States
| | - Anne B. McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| |
Collapse
|
10
|
Morgan WJ, Matthews DA, Ringholm M, Agarwal J, Gong JZ, Ruud K, Allen WD, Stanton JF, Schaefer HF. Geometric Energy Derivatives at the Complete Basis Set Limit: Application to the Equilibrium Structure and Molecular Force Field of Formaldehyde. J Chem Theory Comput 2018; 14:1333-1350. [DOI: 10.1021/acs.jctc.7b01138] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- W. James Morgan
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| | - Devin A. Matthews
- Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, Austin, Texas 78712, United States
| | - Magnus Ringholm
- Hylleraas Centre for Quantum Molecular Science, Department of Chemistry, University of Tromsø − The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Jay Agarwal
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| | - Justin Z. Gong
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Kenneth Ruud
- Hylleraas Centre for Quantum Molecular Science, Department of Chemistry, University of Tromsø − The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Wesley D. Allen
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| | - John F. Stanton
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| |
Collapse
|
11
|
Yurchenko SN, Yachmenev A, Ovsyannikov RI. Symmetry-Adapted Ro-vibrational Basis Functions for Variational Nuclear Motion Calculations: TROVE Approach. J Chem Theory Comput 2017; 13:4368-4381. [DOI: 10.1021/acs.jctc.7b00506] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergei N. Yurchenko
- Department
of Physics and Astronomy, University College London, London, WC1E 6BT, United Kingdom
| | - Andrey Yachmenev
- Center for Free-Electron Laser Science (CFEL), DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Roman I. Ovsyannikov
- Institute of Applied Physics, Russian Academy of Sciences, Ulyanov Street 46, Nizhny Novgorod, Russia 603950
| |
Collapse
|
12
|
Bulik IW, Frisch MJ, Vaccaro PH. Vibrational self-consistent field theory using optimized curvilinear coordinates. J Chem Phys 2017; 147:044110. [DOI: 10.1063/1.4995440] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ireneusz W. Bulik
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Michael J. Frisch
- Gaussian, Inc., 340 Quinnipiac St. Bldg. 40, Wallingford, Connecticut 06492, USA
| | - Patrick H. Vaccaro
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, USA
| |
Collapse
|
13
|
Schmitz G, Christiansen O. Accuracy of Frequencies Obtained with the Aid of Explicitly Correlated Wave Function Based Methods. J Chem Theory Comput 2017; 13:3602-3613. [PMID: 28686442 DOI: 10.1021/acs.jctc.7b00476] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We asses the basis set convergence of harmonic frequencies using different explicitly correlated wave function based methods. All commonly available CCSD(T) variants as well as MP2-F12 and MP4(F12*) are considered, and a hierarchy of the different approaches is established. As for reaction and atomization energies, CCSD(F12*)(T*) is a close approximation to CCSD(F12)(T*) and clearly superior to the other tested approximations. The used scaling for the triples correction enhances the accuracy relative to CCSD(F12*)(T) especially for small basis sets and is very attractive since no additional computational costs are added. However, this scaling slightly breaks size consistency, and therefore we additionally study the accuracy of CCSD(F12*)(T*) and CCSD(F12*)(T) in the context of calculating anharmonic frequencies to check if this causes problems in the generation of the potential energy surface (PES). We find a fast basis set convergence for harmonic and anharmonic frequencies. Already in the cc-pVDZ-F12 basis, the RMSD to the CBS limit is only around 4-5 cm-1.
Collapse
Affiliation(s)
- Gunnar Schmitz
- Department of Chemistry, Aarhus University , Aarhus, Denmark
| | | |
Collapse
|
14
|
Simulating electric field interactions with polar molecules using spectroscopic databases. Sci Rep 2017; 7:45068. [PMID: 28338042 PMCID: PMC5364483 DOI: 10.1038/srep45068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/16/2017] [Indexed: 11/10/2022] Open
Abstract
Ro-vibrational Stark-associated phenomena of small polyatomic molecules are modelled using extensive spectroscopic data generated as part of the ExoMol project. The external field Hamiltonian is built from the computed ro-vibrational line list of the molecule in question. The Hamiltonian we propose is general and suitable for any polar molecule in the presence of an electric field. By exploiting precomputed data, the often prohibitively expensive computations associated with high accuracy simulations of molecule-field interactions are avoided. Applications to strong terahertz field-induced ro-vibrational dynamics of PH3 and NH3, and spontaneous emission data for optoelectrical Sisyphus cooling of H2CO and CH3Cl are discussed.
Collapse
|
15
|
Tennyson J. Perspective: Accurate ro-vibrational calculations on small molecules. J Chem Phys 2016; 145:120901. [DOI: 10.1063/1.4962907] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Jonathan Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| |
Collapse
|
16
|
Pham TN, Ono S, Ohno K. Ab initio molecular dynamics simulation study of successive hydrogenation reactions of carbon monoxide producing methanol. J Chem Phys 2016; 144:144309. [DOI: 10.1063/1.4945628] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Thi Nu Pham
- Department of Physics, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Shota Ono
- Department of Physics, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Kaoru Ohno
- Department of Physics, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| |
Collapse
|
17
|
Duchko AN, Bykov AD. Resummation of divergent perturbation series: Application to the vibrational states of H2CO molecule. J Chem Phys 2015; 143:154102. [PMID: 26493892 DOI: 10.1063/1.4933239] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Large-order Rayleigh-Schrödinger perturbation theory (RSPT) is applied to the calculation of anharmonic vibrational energy levels of H2CO molecule. We use the model of harmonic oscillators perturbed by anharmonic terms of potential energy. Since the perturbation series typically diverge due to strong couplings, we apply the algebraic approximation technique because of its effectiveness shown earlier by Goodson and Sergeev [J. Chem. Phys. 110, 8205 (1999); ibid. 124, 094111 (2006)] and in our previous articles [A. D. Bykov et al. Opt. Spectrosc. 114, 396 (2013); ibid. 116, 598 (2014)]. To facilitate the resummation of terms contributing to perturbed states, when resonance mixing between states is especially strong and perturbation series diverge very quick, we used repartition of the Hamiltonian by shifting the normal mode frequencies. Energy levels obtained by algebraic approximants were compared with the results of variational calculation. It was found that for low energy states (up to ∼5000 cm(-1)), algebraic approximants gave accurate values of energy levels, which were in excellent agreement with the variational method. For highly excited states, strong and multiple resonances complicate series resummation, but a suitable change of normal mode frequencies allows one to reduce the resonance mixing and to get accurate energy levels. The theoretical background of the problem of RSPT series divergence is discussed along with its numerical analysis. For these purposes, the vibrational energy is considered as a function of a complex perturbation parameter. Layout and classification of its singularities allow us to model the asymptotic behavior of the perturbation series and prove the robustness of the algorithm.
Collapse
Affiliation(s)
- A N Duchko
- National Research Tomsk Polytechnic University, Tomsk, Russia
| | - A D Bykov
- V.E. Zuev Institute of Atmospheric Optics, Tomsk, Russia
| |
Collapse
|
18
|
Sibaev M, Crittenden DL. The PyPES library of high quality semi-global potential energy surfaces. J Comput Chem 2015; 36:2200-7. [DOI: 10.1002/jcc.24192] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/19/2015] [Accepted: 08/10/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Marat Sibaev
- Department of Chemistry; University of Canterbury; Christchurch New Zealand
| | | |
Collapse
|
19
|
Yachmenev A, Yurchenko SN. Automatic differentiation method for numerical construction of the rotational-vibrational Hamiltonian as a power series in the curvilinear internal coordinates using the Eckart frame. J Chem Phys 2015; 143:014105. [DOI: 10.1063/1.4923039] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrey Yachmenev
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Sergei N. Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| |
Collapse
|
20
|
Owens A, Yurchenko SN, Yachmenev A, Tennyson J, Thiel W. Accurate ab initio vibrational energies of methyl chloride. J Chem Phys 2015; 142:244306. [DOI: 10.1063/1.4922890] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alec Owens
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
- 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
| | - Andrey Yachmenev
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| |
Collapse
|
21
|
Krasnoshchekov SV, Isayeva EV, Stepanov NF. Criteria for first- and second-order vibrational resonances and correct evaluation of the Darling-Dennison resonance coefficients using the canonical Van Vleck perturbation theory. J Chem Phys 2015; 141:234114. [PMID: 25527926 DOI: 10.1063/1.4903927] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The second-order vibrational Hamiltonian of a semi-rigid polyatomic molecule when resonances are present can be reduced to a quasi-diagonal form using second-order vibrational perturbation theory. Obtaining exact vibrational energy levels requires subsequent numerical diagonalization of the Hamiltonian matrix including the first- and second-order resonance coupling coefficients. While the first-order Fermi resonance constants can be easily calculated, the evaluation of the second-order Darling-Dennison constants requires more complicated algebra for seven individual cases with different numbers of creation-annihilation vibrational quanta. The difficulty in precise evaluation of the Darling-Dennison coefficients is associated with the previously unrecognized interference with simultaneously present Fermi resonances that affect the form of the canonically transformed Hamiltonian. For the first time, we have presented the correct form of the general expression for the evaluation of the Darling-Dennison constants that accounts for the underlying effect of Fermi resonances. The physically meaningful criteria for selecting both Fermi and Darling-Dennison resonances are discussed and illustrated using numerical examples.
Collapse
Affiliation(s)
| | - Elena V Isayeva
- Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Nikolay F Stepanov
- Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia
| |
Collapse
|
22
|
Nikitin AV, Rey M, Tyuterev VG. An efficient method for energy levels calculation using full symmetry and exact kinetic energy operator: Tetrahedral molecules. J Chem Phys 2015; 142:094118. [DOI: 10.1063/1.4913520] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
23
|
Wang Y, Bowman JM. Bend Excitation Is Predicted to Greatly Accelerate Isomerization of trans-Hydroxymethylene to Formaldehyde in the Deep Tunneling Region. J Phys Chem Lett 2015; 6:124-128. [PMID: 26263100 DOI: 10.1021/jz5022944] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Using a new potential energy surface, based on fitting around 33,000 CCSD(T)-F12/aug-cc-pVTZ energies, a robust set of predictions is made for mode-specific isomerization of trans-hydroxymethylene to formaldehyde in the deep tunneling region. The calculations make use of a recent projection model for mode-specific tunneling based on the rectilinear Q(im) path [ Wang , Y. ; Bowman , J. M. J. Chem. Phys. 2013 , 139 , 154303 ]. The most interesting prediction is a large decrease in the half-life from roughly 5 h for the ground vibrational state to roughly 1.5 min and 1 s by excitation of the fundamental and first overtone of the asymmetric bending normal mode, respectively. The properties of the new PES are described along with variational calculations of low-lying vibrational states of trans- and cis-hydroxymethylene.
Collapse
Affiliation(s)
- Yimin Wang
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| |
Collapse
|
24
|
Altnöder J, Krüger K, Borodin D, Reuter L, Rohleder D, Hecker F, Schulz RA, Nguyen XT, Preiß H, Eckhoff M, Levien M, Suhm MA. The Guinness Molecules for the Carbohydrate Formula. CHEM REC 2014; 14:1116-33. [DOI: 10.1002/tcr.201402059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Jonas Altnöder
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Kerstin Krüger
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Dmitriy Borodin
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Lennart Reuter
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Darius Rohleder
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Fabian Hecker
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Roland A. Schulz
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Xuan T. Nguyen
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Helen Preiß
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Marco Eckhoff
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Marcel Levien
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| | - Martin A. Suhm
- Institut für Physikalische Chemie; Georg-August-Universität Göttingen; Tammannstr. 6 D-37077 Göttingen Germany
| |
Collapse
|
25
|
Patrascu AT, Hill C, Tennyson J, Yurchenko SN. Study of the electronic and rovibronic structure of theX2Σ+,A2Π, andB2Σ+states of AlO. J Chem Phys 2014; 141:144312. [DOI: 10.1063/1.4897484] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Andrei T. Patrascu
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Christian Hill
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Jonathan Tennyson
- 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
| |
Collapse
|
26
|
Szidarovszky T, Császár AG. Grid-based empirical improvement of molecular potential energy surfaces. J Phys Chem A 2014; 118:6256-65. [PMID: 25079215 DOI: 10.1021/jp504348f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A grid-based method designed to refine adiabatic potential energy surfaces (PES) of molecules via minimizing a suitable objective function is described. The objective function contains deviations from the reference (experimental) (ro)vibrational energy levels and is based on PES correction values determined at the grid points within a discrete-variable-representation nuclear-motion algorithm and first-order perturbation theory (PT). The proposed PES refinement technique is tested on the ground electronic state of the MgH molecule. The large number of numerical test results obtained suggest the following: (1) first-order PT is able to yield accurate correction values at the grid points representing the PES, and for practical cases there seems to be no need to go to higher orders of PT; (2) with the number of grid points greatly exceeding the number of experimental energy levels included in the refinement procedure, terms additional to the "obs-calc" term, including numerical first and second derivatives of the correction surface, are necessary in the objective function to arrive at a physically meaningful, "smooth" correction surface; (3) for a given J rotational quantum number, the corrected PES is able to reproduce experimental (ro)vibrational energies to within tenths of cm(-1) if they are included in the refinement or interpolated between states that are involved in the optimization, whereas extrapolated states tend to have somewhat larger remaining discrepancies; (4) the PES refined only for the J = 0 states introduces a minor systematic error for J > 0 states, with discrepancies growing with J; (5) when the number of experimental energies included in the refinement greatly exceeds the number of grid points upon which the PES is optimized, the systematic error of treating states with different J rotational quantum numbers can be reduced and an impressive average accuracy can be achieved for all rovibrational states; and (6) in the case of quasibound (also known as resonance) rovibrational states, energies can be computed to accuracies similar to those of the bound states and excellent lifetimes (widths) can also be determined. Changes in thermochemical functions upon inclusion of quasibound states during direct summation is discussed.
Collapse
Affiliation(s)
- Tamás Szidarovszky
- MTA-ELTE Research Group on Complex Chemical Systems, P.O. Box 32, H-1518 Budapest 112, Hungary
| | | |
Collapse
|
27
|
Martin JML, Kesharwani MK. Assessment of CCSD(T)-F12 Approximations and Basis Sets for Harmonic Vibrational Frequencies. J Chem Theory Comput 2014; 10:2085-90. [DOI: 10.1021/ct500174q] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jan M. L. Martin
- Department
of Organic Chemistry, Weizmann Institute of Science, 76100 Reh̲ovot, Israel
| | - Manoj K. Kesharwani
- Department
of Organic Chemistry, Weizmann Institute of Science, 76100 Reh̲ovot, Israel
| |
Collapse
|
28
|
Krasnoshchekov SV, Stepanov NF. Polyad quantum numbers and multiple resonances in anharmonic vibrational studies of polyatomic molecules. J Chem Phys 2013; 139:184101. [DOI: 10.1063/1.4829143] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
29
|
Abstract
AbstractWe perform converged high precision variational calculations to determine the frequencies of the vibrational levels in S0 HDCO, extending up to 5000 cm−1 of vibrational excitation energy. For these calculations we use our specific vibrational method (recently employed for studies on H2CO and D2CO), consisting of a combination of a search/selection algorithm and a Lanczos iteration procedure and based on the Martin, Lee, Taylor potential energy surface for formaldehyde. The calculated level structure is compared to the recently measured frequencies by Ellsworth et al. in order to improve their assignments and further clarify the vibrational mixing pattern and vibrational resonances in HDCO that are very different from the other more symmetric formaldehyde species H2CO and D2CO studied recently.
Collapse
|
30
|
Rashev S, Moule DC, Rashev V. Variational study on the vibrational level structure and vibrational level mixing of highly vibrationally excited S₀ D₂CO. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 97:111-118. [PMID: 22750345 DOI: 10.1016/j.saa.2012.05.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 05/22/2012] [Accepted: 05/26/2012] [Indexed: 06/01/2023]
Abstract
We perform converged high precision variational calculations to determine the frequencies of a large number of vibrational levels in S(0) D(2)CO, extending from low to very high excess vibrational energies. For the calculations we use our specific vibrational method (recently employed for studies on H(2)CO), consisting of a combination of a search/selection algorithm and a Lanczos iteration procedure. Using the same method we perform large scale converged calculations on the vibrational level spectral structure and fragmentation at selected highly excited overtone states, up to excess vibrational energies of ∼17,000 cm(-1), in order to study the characteristics of intramolecular vibrational redistribution (IVR), vibrational level density and mode selectivity.
Collapse
Affiliation(s)
- Svetoslav Rashev
- Institute of Solid State Physics, Bulgarian Academy of Sciences, Tsarigradsko chaussee 72, 1784 Sofia, Bulgaria.
| | | | | |
Collapse
|
31
|
Krasnoshchekov SV, Isayeva EV, Stepanov NF. Numerical-analytic implementation of the higher-order canonical Van Vleck perturbation theory for the interpretation of medium-sized molecule vibrational spectra. J Phys Chem A 2012; 116:3691-709. [PMID: 22369280 DOI: 10.1021/jp211400w] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Anharmonic vibrational states of semirigid polyatomic molecules are often studied using the second-order vibrational perturbation theory (VPT2). For efficient higher-order analysis, an approach based on the canonical Van Vleck perturbation theory (CVPT), the Watson Hamiltonian and operators of creation and annihilation of vibrational quanta is employed. This method allows analysis of the convergence of perturbation theory and solves a number of theoretical problems of VPT2, e.g., yields anharmonic constants y(ijk), z(ijkl), and allows the reliable evaluation of vibrational IR and Raman anharmonic intensities in the presence of resonances. Darling-Dennison and higher-order resonance coupling coefficients can be reliably evaluated as well. The method is illustrated on classic molecules: water and formaldehyde. A number of theoretical conclusions results, including the necessity of using sextic force field in the fourth order (CVPT4) and the nearly vanishing CVPT4 contributions for bending and wagging modes. The coefficients of perturbative Dunham-type Hamiltonians in high-orders of CVPT are found to conform to the rules of equality at different orders as earlier proven analytically for diatomic molecules. The method can serve as a good substitution of the more traditional VPT2.
Collapse
|
32
|
Rashev S, Moule DC. Variational study on the vibrational level structure and IVR behavior of highly vibrationally excited S0 formaldehyde. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 87:286-292. [PMID: 22185953 DOI: 10.1016/j.saa.2011.11.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/17/2011] [Accepted: 11/24/2011] [Indexed: 05/31/2023]
Abstract
We perform large scale converged variational vibrational calculations on S(0) formaldehyde up to very high excess vibrational energies (E(v)), E(v)∼17,000cm(-1), using our vibrational method, consisting of a specific search/selection/Lanczos iteration procedure. Using the same method we investigate the vibrational level structure and intramolecular vibrational redistribution (IVR) characteristics for various vibrational levels in this energy range in order to assess the onset of IVR.
Collapse
Affiliation(s)
- Svetoslav Rashev
- Institute of Solid State Physics, Bulgarian Academy of Sciences, Tsarigradsko Chaussee 72, 1784 Sofia, Bulgaria.
| | | |
Collapse
|
33
|
Yachmenev A, Yurchenko SN, Ribeyre T, Thiel W. High-level ab initio potential energy surfaces and vibrational energies of H2CS. J Chem Phys 2011; 135:074302. [DOI: 10.1063/1.3624570] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|