Mixed Quantum/Classical Calculations of Rotationally Inelastic Scattering in the CO + CO System: A Comparison With Fully Quantum Results

Authors

Dulat Bostan, Marquette University
Bikramaditya Mandal, Marquette University
Carolin Joy, Marquette University
Michał Żółtowski, University of Rennes
François Lique, University of Rennes
Jérôme Loreau, KU Leuven
Ernesto Quintas-Sánchez, Missouri University of Science and Technology
Adrian Batista-Planas, Missouri University of Science and Technology
Richard Dawes, Missouri University of Science and Technology
Dmitri Babikov, Marquette UniversityFollow

Document Type

Article

Publication Date

2024

Publisher

Royal Society of Chemistry

Source Publication

Physical Chemistry Chemical Physics

Source ISSN

1463-9076

Original Item ID

DOI: 10.1039/D3CP05369E

Abstract

An updated version of the CO + CO potential energy surface from [R. Dawes, X. G. Wang and T. Carrington, J. Phys. Chem. A 2013, 117, 7612] is presented, that incorporates an improved treatment of the asymptotic behavior. It is found that this new surface is only slightly different from the other popular PES available for this system in the literature [G. W. M. Vissers, P. E. S. Wormer and A. Van Der Avoird, Phys. Chem. Chem. Phys. 2003, 5, 4767]. The differences are quantified by expanding both surfaces over a set of analytic functions and comparing the behavior of expansion coefficients along the molecule–molecule distance R. It is shown that all expansion coefficients behave similarly, except in the very high energy range at small R where the PES is repulsive. That difference has no effect on low collision-energy dynamics, which is explored via inelastic scattering calculations carried out using the MQCT program which implements the mixed quantum/classical theory for molecular energy exchange processes. The validity of MQCT predictions of state-to-state transition cross sections for CO + CO is also tested by comparison against full-quantum coupled-states calculations. In all cases MQCT gives reliable results, except at very low collision energy where the full-quantum calculations predict strong oscillations of state-to-state transition cross sections due to resonances. For strong transitions with large cross sections, the results of MQCT are reliable, especially at higher collision energy. For weaker transitions, and lower collision energies, the cross sections predicted by MQCT may be up to a factor of 2–3 different from those obtained by full-quantum calculations.

Comments

Published version. Physical Chemistry Chemical Physics, Vol. 26 (2024): 6627-6637. DOI. © 2024 Royal Society of Chemistry. Used with permission.

Recommended Citation

Bostan, Dulat; Mandal, Bikramaditya; Joy, Carolin; Żółtowski, Michał; Lique, François; Loreau, Jérôme; Quintas-Sánchez, Ernesto; Batista-Planas, Adrian; Dawes, Richard; and Babikov, Dmitri, "Mixed Quantum/Classical Calculations of Rotationally Inelastic Scattering in the CO + CO System: A Comparison With Fully Quantum Results" (2024). Chemistry Faculty Research and Publications. 1078.
https://epublications.marquette.edu/chem_fac/1078