Reactive Rate Constants for the C+ + H2(v = 0, 1) Reaction: An Accurate State-to-state Quantum Dynamical Study

Abstract

Abstract The accurately calculated thermal rate constants of the C+ + H2(v = 0, 1) reaction are important for estimating the CH+ emission spectra in different astronomical environments. In this study, reactive quantum dynamics of the C+ + H2(v = 0, 1) reaction have been investigated with the time-dependent wave packet method on the high-quality potential energy surface recently developed by Guo et al. The simulated total cross sections are compared in detail with previous experimental measurements and dynamical results. The calculated total rate constants are found to be in good agreement with previous quasi-classical results by Herráez-Aguilar et al., except for the v = 0 reaction at low temperatures. The ro-vibrational state-resolved rate constants show that the CH+ product, obtained from both the v = 0 and v = 1 reactions, is significantly populated in the vibrational ground but rotational excited states. In particular, for the v = 0 reaction, the CH+ product is preferably formed at j′ = 4, 5 rotational levels, while the CH+ product for the v = 1 reaction prefers rotational excitation j′ = 6–8. This finding varies with previous J-shifting calculations by Zanchet et al., owing to the different potential energy surface and methodology employed in the calculations.