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Loreau J, van der Avoird A. Vibrational energy transfer in ammonia-helium collisions. Faraday Discuss 2024. [PMID: 38787637 DOI: 10.1039/d3fd00180f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
While the rotational energy transfer of ammonia by rare gas atoms and hydrogen molecules has been the focus of many studies, little is known about its vibrational relaxation, even though transitions involving the umbrella bending mode have been observed in many astrophysical environments. Here we explore the vibrational relaxation of the umbrella mode of ammonia induced by collisions with helium atoms by means of the close-coupling method on an ab initio potential energy surface. We compute cross sections up to kinetic energies of 1500 cm-1 and rate coefficients up to a temperature of 300 K for vibrational, rotational, and inversion transitions involving the lowest two vibrational states. We show that vibrational relaxation is much less efficient than rotation-inversion relaxation, although the rate coefficients for vibrational relaxation strongly increase with the temperature. We also observe important differences for vibrationally-elastic transitions within the lowest two vibrational states, i.e., for rotation-inversion transitions. These are a direct consequence of the difference in the tunnelling splitting of the lowest inversion levels.
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Affiliation(s)
- Jérôme Loreau
- KU Leuven, Department of Chemistry, B-3001 Leuven, Belgium.
| | - Ad van der Avoird
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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2
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García-Vázquez RM, Faure A, Stoecklin T. Bending Relaxation of H 2 O by Collision with Para- and Ortho-H 2. Chemphyschem 2024; 25:e202300698. [PMID: 37988180 DOI: 10.1002/cphc.202300698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/21/2023] [Accepted: 11/21/2023] [Indexed: 11/23/2023]
Abstract
We extend our recent theoretical work on the bending relaxation of H2 O in collisions with H2 by including the three water modes of vibration coupled with rotation, as well as the rotation of H2 . Our full quantum close-coupling method (excluding the H2 vibration) is combined with a high-accuracy nine-dimensional potential energy surface. The collisions of para-H2 O and ortho-H2 O with the two spin modifications of H2 are considered and compared for several initial states of H2 O. The convergence of the results as a function of the size of the rotational basis set of the two colliders is discussed. In particular, near-resonant energy transfer between H2 O and H2 is found to control the vibrational relaxation process, with a dominant contribution of transitions withΔ j 2 = j 2 f - j 2 i ${{\rm{\Delta }}j_2 = j_2^f - j_2^i }$ =+ 2 , + 4 ${ + 2, + 4}$ ,j 2 i ${j_2^i }$ andj 2 f ${j_2^f }$ being respectively the H2 initial and final rotational quantum numbers. Finally, the calculated value of the H2 O bending relaxation rate coefficient at 295 K is found to be in excellent agreement with its experimental estimate.
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Affiliation(s)
| | | | - Thierry Stoecklin
- UMR5255-CNRS, Université de Bordeaux, 351 cours de la libération, F-33405, Talence, France
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Stoecklin T, Cabrera-González LD, Denis-Alpizar O, Páez-Hernández D. A close coupling study of the bending relaxation of H 2O by collision with He. J Chem Phys 2021; 154:144307. [PMID: 33858145 DOI: 10.1063/5.0047718] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a close coupling study of the bending relaxation of H2O by collision with He, taking explicitly into account the bending-rotation coupling within the rigid-bender close-coupling method. A 4D potential energy surface is developed based on a large grid of ab initio points calculated at the coupled-cluster single double triple level of theory. The bound states energies of the He-H2O complex are computed and found to be in excellent agreement with previous theoretical calculations. The dynamics results also compare very well with the rigid-rotor results available in the Basecol database and with experimental data for both rotational transitions and bending relaxation. The bending-rotation coupling is also demonstrated to be very efficient in increasing bending relaxation when the rotational excitation of H2O increases.
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Affiliation(s)
- Thierry Stoecklin
- Institut des Sciences Moléculaires, Université de Bordeaux, CNRS UMR 5255, 33405 Talence Cedex, France
| | - Lisán David Cabrera-González
- Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andres Bello, República 275, Santiago, Chile
| | - Otoniel Denis-Alpizar
- Núcleo de Astroquímica y Astrofísica, Instituto de Ciencias Químicas Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, Av. Pedro de Valdivia 425, Providencia, Santiago, Chile
| | - Dayán Páez-Hernández
- Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andres Bello, República 275, Santiago, Chile
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Stoecklin T, Denis-Alpizar O, Clergerie A, Halvick P, Faure A, Scribano Y. Rigid-Bender Close-Coupling Treatment of the Inelastic Collisions of H2O with para-H2. J Phys Chem A 2019; 123:5704-5712. [DOI: 10.1021/acs.jpca.9b04052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thierry Stoecklin
- UMR5255-CNRS, Université de Bordeaux, 351 cours de la libération, F-33405 Talence, France
| | - Otoniel Denis-Alpizar
- Instituto de Ciencias Químicas Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, El Llano Subercaseaux 2801, San Miguel, Santiago, Chile
| | - Alexandre Clergerie
- UMR5255-CNRS, Université de Bordeaux, 351 cours de la libération, F-33405 Talence, France
| | - Philippe Halvick
- UMR5255-CNRS, Université de Bordeaux, 351 cours de la libération, F-33405 Talence, France
| | - Alexandre Faure
- CNRS, IPAG, Université Grenoble Alpes, F-38000 Grenoble, France
| | - Yohann Scribano
- Laboratoire Univers et Particules de Montpellier, UMR-CNRS 5299, Université de Montpellier, F-34095 Montpellier Cedex, France
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Tkáč O, Ma Q, Stei M, Orr-Ewing AJ, Dagdigian PJ. Rotationally inelastic scattering of methyl radicals with Ar and N2. J Chem Phys 2015; 142:014306. [PMID: 25573560 DOI: 10.1063/1.4904901] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The rotationally inelastic scattering of methyl radical with Ar and N2 is examined at collision energies of 330 ± 25 cm(-1) and 425 ± 50 cm(-1), respectively. Differential cross sections (DCSs) were measured for different final n' rotational levels (up to n' = 5) of the methyl radicals, averaged over k' sub-levels, using a crossed molecular beam machine with velocity map imaging. For Ar as a collision partner, we present a newly constructed ab initio potential energy surface and quantum mechanical scattering calculations of state-resolved DCSs. These computed DCSs agree well with the measurements. The DCSs for both Ar and N2 collision partners are strongly forward peaked for all spectroscopic lines measured. For scattering angles below 60°, the theoretical CD3-Ar DCSs show diffraction oscillations that become less pronounced as n' increases, but these oscillations are not resolved experimentally. Comparisons are drawn with our recently reported DCSs for scattering of methyl radicals with He atoms.
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Affiliation(s)
- Ondřej Tkáč
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Qianli Ma
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
| | - Martin Stei
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Paul J Dagdigian
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
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Ma L, Dagdigian PJ, Alexander MH. Theoretical investigation of the relaxation of the bending mode of CH₂(X̃) by collisions with helium. J Chem Phys 2014; 141:214305. [PMID: 25481142 DOI: 10.1063/1.4902004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have earlier determined the dependence on the bending angle of the interaction of the methylene radical (CH2) in its X̃³B₁ state with He [L. Ma, P. J. Dagdigian, and M. H. Alexander, J. Chem. Phys. 136, 224306 (2012)]. By integration over products of the bending vibrational wave function, in a quantum close-coupled treatment we have calculated cross sections for the ro-vibrational relaxation of CH 2(X̃). Specifically, we find that cross sections for a loss of one vibrational quantum (v(b) = 2 → 1 and 1 → 0) are roughly two orders of magnitude smaller, and those for a loss of two vibrational quanta (v(b) = 2 → 0) four orders of magnitude smaller, than those for pure rotational relaxation. In addition, no clear cut dependence on the energy gap is seen.
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Affiliation(s)
- Lifang Ma
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742-2021, USA
| | - Paul J Dagdigian
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
| | - Millard H Alexander
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742-2021, USA
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Jasper AW, Kamarchik E, Miller JA, Klippenstein SJ. First-principles binary diffusion coefficients for H, H2, and four normal alkanes + N2. J Chem Phys 2014; 141:124313. [DOI: 10.1063/1.4896368] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ahren W. Jasper
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA
| | - Eugene Kamarchik
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA
| | - James A. Miller
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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Tkáč O, Rusher CA, Greaves SJ, Orr-Ewing AJ, Dagdigian PJ. Differential and integral cross sections for the rotationally inelastic scattering of methyl radicals with H2and D2. J Chem Phys 2014; 140:204318. [DOI: 10.1063/1.4879618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Tkáč O, Orr-Ewing AJ, Dagdigian PJ, Alexander MH, Onvlee J, van der Avoird A. Collision dynamics of symmetric top molecules: a comparison of the rotationally inelastic scattering of CD3 and ND3 with He. J Chem Phys 2014; 140:134308. [PMID: 24712794 DOI: 10.1063/1.4869596] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We compare rotationally inelastic scattering of deuterated methyl radicals (CD3) and ammonia (ND3) in collisions with helium using close-coupling quantum-mechanical scattering calculations performed with ab initio potential energy surfaces (PESs). The theoretical methods have been rigorously tested against angle-resolved experimental measurements obtained using crossed molecular beam apparatuses in combination with velocity map imaging [O. Tkáč, A. G. Sage, S. J. Greaves, A. J. Orr-Ewing, P. J. Dagdigian, Q. Ma, and M. H. Alexander, Chem. Sci. 4, 4199 (2013); O. Tkáč, A. K. Saha, J. Onvlee, C.-H. Yang, G. Sarma, C. K. Bishwakarma, S. Y. T. van de Meerakker, A. van der Avoird, D. H. Parker, and A. J. Orr-Ewing, Phys. Chem. Chem. Phys. 16, 477 (2014)]. Common features of the scattering dynamics of these two symmetric top molecules, one closed-shell and the other an open-shell radical, are identified and discussed. Two types of anisotropies in the PES influence the interaction of an atom with a nonlinear polyatomic molecule. The effects of these anisotropies can be clearly seen in the state-to-state integral cross sections out of the lowest CD3 rotational levels of each nuclear spin symmetry at a collision energy of 440 cm(-1). Similarities and differences in the differential cross sections for the ND3-He and CD3-He systems can be linked to the coupling terms derived from the PESs which govern particular initial to final rotational level transitions.
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Affiliation(s)
- Ondřej Tkáč
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Paul J Dagdigian
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
| | - Millard H Alexander
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742-2021, USA
| | - Jolijn Onvlee
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
| | - Ad van der Avoird
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands
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10
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Tkáč O, Sage AG, Greaves SJ, Orr-Ewing AJ, Dagdigian PJ, Ma Q, Alexander MH. Rotationally inelastic scattering of CD3 and CH3 with He: comparison of velocity map-imaging data with quantum scattering calculations. Chem Sci 2013. [DOI: 10.1039/c3sc52002a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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