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Arndt PT, Huennekens J, Packard C, Tran V, Carey J, Livingston R, Marcune VM, Rowe BA, Ng J, Qi J, Lyyra AM, Ahmed EH. The effect of collisions on the rotational angular momentum of diatomic molecules studied using polarized light. J Chem Phys 2020; 153:184310. [DOI: 10.1063/5.0024380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- P. T. Arndt
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - J. Huennekens
- Physics Department, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | - C. Packard
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - V. Tran
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - J. Carey
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - R. Livingston
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - V. M. Marcune
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - B. A. Rowe
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - J. Ng
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - J. Qi
- Department of Physics and Astronomy, Penn State University, Berks Campus, Reading, Pennsylvania 19610, USA
| | - A. M. Lyyra
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - E. H. Ahmed
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122, USA
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Fanthorpe J, Gao Y, Stewart B. Rotational Energy Transfer in Highly Excited States of Lithium Dimer: Experiment and Modeling. J Phys Chem A 2020; 124:7373-7379. [PMID: 32835478 DOI: 10.1021/acs.jpca.0c04960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report level-resolved rate coefficients for collision-induced rotational energy transfer in the 7Li2*-Ne system, with 7Li2* in the highly electronically excited E(3)1Σg+(vi = 4, ji = 31) and F(4)1Σg+(vi = 10, ji = 31) states. The distributions of rate coefficients are strikingly different from those previously measured for the A(1)1Σu+(vi = 2-24, ji = 30) state of the same molecule, falling off much more rapidly with increasing rotational quantum number change |Δj|. The reason for the difference was explored by means of an inverse Monte Carlo approach employing classical trajectories and a model potential, which was adjusted to give agreement with experiment. The modeling strongly suggests that the E and F state interaction potentials are much more nearly isotropic than that of the A state. The resulting dramatic reduction in rate coefficient, especially for large |Δj|, may be relevant in the relaxation of gases at high temperatures.
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Affiliation(s)
- Jacob Fanthorpe
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Yunxiao Gao
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Brian Stewart
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, United States
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Corongiu G, Mella M. Vibrationally Inelastic Collision Between Li2(ν = 0) and Li: Direct and Postponed Elongation Mechanisms. J Phys Chem A 2015; 119:12945-52. [PMID: 26652287 DOI: 10.1021/acs.jpca.5b07184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanism for vibrational inelastic excitation during the collision between Li2(ν = 0) and Li was investigated exploiting classical trajectory simulations over a potential energy surface generated by fitting valence full configuration interaction calculations employing a large basis set. From the trajectory results, it emerges that the vibrational excitation in noncapture collisions presents uniquely a forward-scattered projectile for the highest levels of excitation (ΔE(0 → ν') ≃ Ecoll). For lower ν', a minor contribution presenting a backward-scattered projectile appears, which, however, has its major contribution coming from a "slingshot"-like (orbiting) mechanism exploiting the attractive features of the Li3 potential energy surface rather than a direct recoil.
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Affiliation(s)
- Giorgina Corongiu
- Dipartimento di Scienza ed Alta Tecnologia, Università dell'Insubria , via Valleggio 11, 22100 Como, Italy
| | - Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università dell'Insubria , via Valleggio 11, 22100 Como, Italy
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Esposito F, Coppola CM, De Fazio D. Complementarity between Quantum and Classical Mechanics in Chemical Modeling. The H + HeH+ → H2 + + He Reaction: A Rigourous Test for Reaction Dynamics Methods. J Phys Chem A 2015; 119:12615-26. [PMID: 26583384 DOI: 10.1021/acs.jpca.5b09660] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this work we present a dynamical study of the H + HeH+ → H2+ + He reaction in a collision energy range from 0.1 meV to 10 eV, suitable to be used in applicative models. The paper extends and complements a recent work [ Phys. Chem. Chem. Phys. 2014, 16, 11662] devoted to the characterization of the reactivity from the ultracold regime up to the three-body dissociation breakup. In particular, the accuracy of the quasi-classical trajectory method below the three-body dissociation threshold has been assessed by a detailed comparison with previous calculations performed with different reaction dynamics methods, whereas the reliability of the results in the high energy range has been checked by a direct comparison with the available experimental data. Integral cross sections for several HeH+ roto-vibrational states have been analyzed and used to understand the extent of quantum effects in the reaction dynamics. By using the quasi-classical trajectory method and quantum mechanical close coupling data, respectively, in the high and low collision energy ranges, we obtain highly accurate thermal rate costants until 15 000 K including all (178) the roto-vibrational bound and quasi-bound states of HeH+. The role of the collision-induced dissociation is also discussed and explicitly calculated for the ground roto-vibrational state of HeH+.
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Affiliation(s)
- Fabrizio Esposito
- Consiglio Nazionale delle Ricerche, Istituto di Nanotecnologia, via Amendola 122/d, 70126 Bari, Italy
| | - Carla Maria Coppola
- Consiglio Nazionale delle Ricerche, Istituto di Nanotecnologia, via Amendola 122/d, 70126 Bari, Italy.,INAF-Osservatorio Astrofisico di Arcetri , 50125 Firenze, Italy
| | - Dario De Fazio
- Consiglio Nazionale delle Ricerche, Istituto di Struttura della Materia, Area della Ricerca di Roma 1, 00016 Roma, Italy
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Forthomme D, Hause ML, Yu HG, Dagdigian PJ, Sears TJ, Hall GE. Doppler-Resolved Kinetics of Saturation Recovery. J Phys Chem A 2015; 119:7439-50. [PMID: 25815527 DOI: 10.1021/acs.jpca.5b00628] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Frequency-modulated laser transient absorption has been used to monitor the ground-state rotational energy-transfer rates of CN radicals in a double-resonance, depletion recovery experiment. When a pulsed laser is used to burn a hole in the equilibrium ground-state population of one rotational state without velocity selection, the population recovery rate is found to depend strongly on the Doppler detuning of a narrow-band probe laser. Similar effects should be apparent for any relaxation rate process that competes effectively with velocity randomization. Alternative methods of extracting thermal rate constants in the presence of these non-thermal conditions are evaluated. Total recovery rate constants, analogous to total removal rate constants in an experiment preparing a single initial rotational level, are in good agreement with quantum scattering calculations, but are slower than previously reported experiments and show qualitatively different rotational state dependence between Ar and He collision partners. Quasi-classical trajectory studies confirm that the differing rotational state dependence is primarily a kinematic effect.
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Affiliation(s)
- Damien Forthomme
- †Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Michael L Hause
- †Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Hua-Gen Yu
- †Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Paul J Dagdigian
- ‡Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Trevor J Sears
- †Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States.,§Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Gregory E Hall
- †Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
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Dagdigian PJ. Theoretical investigation of collisional energy transfer in polyatomic intermediates. INT REV PHYS CHEM 2013. [DOI: 10.1080/0144235x.2012.758543] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Dagdigian PJ, Alexander MH. Theoretical study of the vibrational relaxation of the methyl radical in collisions with helium. J Chem Phys 2013; 138:104317. [DOI: 10.1063/1.4794167] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ruiz A, Palao JP. Effects of classical nonlinear resonances in grazing diatom-surface collisions. J Chem Phys 2012; 137:084302. [DOI: 10.1063/1.4746689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rosenberry M, Marhatta R, Stewart B. Comparison of rotationally inelastic rate constants for <mml:math altimg="si3.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Li</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mspace width="0.35em"/><mml:msup><mml:mrow><mml:mtext>A</mml:mtext></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msup><mml:msubsup><mml:mrow><mml:mi mathvariant="normal">Σ</mml:mi></mml:mrow><mml:mrow><mml:mi>u</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mrow><mml:mi>v</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>5</mml:mn><mml:mtext>,</mml:mtext><mml:msub><mml:mrow><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>30</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math> + Ne measured using pulsed and cw lasers. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2011.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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