Decoding vibrational energy transfer in CO–O2 collisions: Vibrational state-to-state rate coefficient datasets on a new potential energy surface

Abstract

Energy exchanges in collisions between carbon monoxide (CO) and molecular oxygen (O2) are investigated in this paper, and comprehensive datasets of state-to-state rate coefficients for vibration-to-vibration (V–V) and vibration-to-translation/rotation (V–T/R) energy transfer processes are obtained. The data are generated using a mixed quantum–classical (MQC) dynamical method on a newly developed potential energy surface, which is optimized against available experimental data and high-level ab initio calculations. The MQC dataset covers a broad temperature range from 100 to 5000 K, with additional extension through a Gaussian process regression technique to incorporate key V–T/R and near-resonant V–V processes, which include vibrational states of vCO up to 30, as well as the full vibrational ladder of O2 up to its dissociation limit. The results reveal the dominance of V–V kinetics at lower temperatures and the increasing importance of V–T/R processes at higher temperatures. The present dataset addresses a critical gap in the kinetic modeling of CO + O2 collisions in high-temperature gaseous environments.