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Szabó P, Gustafsson M. Polyatomic radiative association by quasiclassical trajectory calculations: Formation of HCN and HNC molecules in H + CN collisions. J Chem Phys 2023; 159:144112. [PMID: 37831719 DOI: 10.1063/5.0170577] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 08/21/2023] [Indexed: 10/15/2023] Open
Abstract
We have developed the polyatomic extension of the established [M. Gustafsson, J. Chem. Phys. 138, 074308 (2013)] classical theory of radiative association in the absence of electronic transitions. The cross section and the emission spectrum of the process is calculated by a quasiclassical trajectory method combined with the classical Larmor formula which can provide the radiated power in collisions. We have also proposed a Monte Carlo scheme for efficient computation of ro-vibrationally quantum state resolved cross sections for radiative association. Besides the method development, the global potential energy and dipole surfaces for H + CN collisions have been calculated and fitted to test our polyatomic semiclassical method.
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Affiliation(s)
- Péter Szabó
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
- Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Avenue Circulaire 3, 1180 Brussels, Belgium
- Applied Physics, Division of Materials Science, Department of Engineering Science and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden
| | - Magnus Gustafsson
- Applied Physics, Division of Materials Science, Department of Engineering Science and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden
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Gao D, Xin X, Wang D, Szabó P, Lendvay G. Theoretical dynamics studies of the CH 3 + HBr → CH 4 + Br reaction: integral cross sections, rate constants and microscopic mechanism. Phys Chem Chem Phys 2022; 24:10548-10560. [PMID: 35445671 DOI: 10.1039/d2cp00066k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Quantum and quasi-classical dynamics calculations have been performed for the reaction of HBr with CH3. The accurate ab initio-based potential energy surface function developed earlier for this reaction displays a potential well corresponding to a reactant complex and a submerged potential barrier. The integral cross sections were calculated on this potential energy surface using both a six-degree-of-freedom reduced dimensional quantum dynamics and the quasi-classical trajectory method and very good agreement was found between the two approaches. The cross sections were found to diverge when the collision energy decreases, indicating that the reactant attraction is responsible for the dynamics at low collision energy. The quantum mechanical and the quasi-classical rate constants also agree very well and almost exactly reproduce the experimental results at low temperatures up to 540 K. The negative activation energy observed experimentally is confirmed by the calculations and is a consequence of the long-range attraction between the reactants. From the classical trajectories mechanistic details have been extracted. It is found that at very low collision energy, the reacting system crosses the potential barrier because the forces within the complex guide them, although some 30% is reflected from the product side of the barrier. When the collision energy increases, the system does not follow the most favorable path and the reactants are, with increasing probability, reflected from the repulsive walls of the nonreactive parts of the reactants, providing a picture beyond the decreasing excitation function.
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Affiliation(s)
- Delu Gao
- College of Physics and Electronics, Shandong Normal University, Jinan 250014, Shandong, China.
| | - Xin Xin
- College of Physics and Electronics, Shandong Normal University, Jinan 250014, Shandong, China.
| | - Dunyou Wang
- College of Physics and Electronics, Shandong Normal University, Jinan 250014, Shandong, China.
| | - Péter Szabó
- Faculté des Sciences, des Technologies et de Médecine, Département Physique et sciences des matériaux, Campus Limpertsberg, Université du Luxembourg 162 A, avenue de la, Faïencerie L-1511, Luxembourg
| | - György Lendvay
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, H-1117 Budapest, Hungary. .,Department of General and Inorganic Chemistry, University of Pannonia, Egyetem utca 10, Veszprém, H-8200, Hungary
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Marjollet A, Inhester L, Welsch R. Initial state-selected scattering for the reactions H + CH4/CHD3 and F + CHD3 employing ring polymer molecular dynamics. J Chem Phys 2022; 156:044101. [DOI: 10.1063/5.0076216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A. Marjollet
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
- Department of Physics, Universität Hamburg, Notkestr. 9-11, 22607 Hamburg, Germany
| | - L. Inhester
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - R. Welsch
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
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Nagy T, Lendvay G. Beyond the normal mode picture: the importance of the reactant’s intramolecular mode coupling in quasiclassical trajectory simulations. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1939451] [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)
- Tibor Nagy
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - György Lendvay
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
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Sanches-Neto FO, Coutinho ND, Palazzetti F, Carvalho-Silva VH. Temperature dependence of rate constants for the H(D) + CH4 reaction in gas and aqueous phase: deformed Transition-State Theory study including quantum tunneling and diffusion effects. Struct Chem 2019. [DOI: 10.1007/s11224-019-01437-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nagy T, Vikár A, Lendvay G. A general formulation of the quasiclassical trajectory method for reduced-dimensionality reaction dynamics calculations. Phys Chem Chem Phys 2018; 20:13224-13240. [PMID: 29722776 DOI: 10.1039/c8cp01600c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dimension reduction by freezing the unimportant coordinates is widely used in intramolecular and reaction dynamics calculations when the solution of the accurate full-dimensional nuclear Schrödinger equation is not feasible. In this paper we report on a novel form of the exact classical internal-coordinate Hamiltonian for full and reduced-dimensional vibrational motion of polyatomic molecules with the purpose of using it in quasiclassical trajectory (QCT) calculations. The derivation is based on the internal to body-fixed frame transformation, as in the t-vector formalism, however it does not require the introduction of rotational variables to allow cancellation of non-physical rotations within the body-fixed frame. The formulas needed for QCT calculations: normal mode analysis and state sampling as well as for following the dynamics and normal-mode quantum number assignment at instantaneous states are presented. The procedure is demonstrated on the CH4, CD4, CH3D and CHD3 isotopologs of methane using three reduced-dimensional models, which were previously used in quantum reactive scattering studies of the CH4 + X → CH3 + HX type reactions. The reduced-dimensional QCT methodology formulated this way combined with full-dimensional QCT calculations makes possible the classical validation of reduced-dimensional models that are used in the quantum mechanical description of the nuclear dynamics in reactive systems [A. Vikár et al., J. Phys. Chem. A, 2016, 120, 5083-5093].
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Affiliation(s)
- Tibor Nagy
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary.
| | - Anna Vikár
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary.
| | - György Lendvay
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary. and Department of General and Inorganic Chemistry, University of Pannonia, Egyetem u. 10, H-8800 Veszprém, Hungary
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Larsson HR, Hartke B, Tannor DJ. Efficient molecular quantum dynamics in coordinate and phase space using pruned bases. J Chem Phys 2016; 145:204108. [DOI: 10.1063/1.4967432] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- H. R. Larsson
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - B. Hartke
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - D. J. Tannor
- Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
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