Quasi-classical trajectory study of the H + CO2 → HO + CO reaction on a new ab initio based potential energy surface

A detailed quasi-classical trajectory study of the H + CO(2) → HO + CO reaction is reported on an accurate potential energy surface based on ab initio data. The influence of the vibrational and rotational excitations of CO(2) was investigated up to the collision energy of 2.35 eV. It was found that the total reaction integral cross section increases monotonically with the collision energy, consistent with experimental results. The excitation of the CO(2) bending vibration enhances the reaction, while the excitation in its asymmetric stretching vibration inhibits the reaction. The calculated thermal rate constants are in excellent agreement with experiment. At the state-to-state level, the rotational state distributions of the HO product are in good agreement with experimental results, while those for the CO product are much hotter than measurements. The calculated differential cross sections are dominated by forward scattering, suggesting that the lifetime of the HOCO intermediate may not be sufficiently long to render the reaction completely statistical.