Quantum dynamics of the reaction of hydrogen atom with methane

Time-independent quantum scattering calculations on the H+CH4 → H2+CH3 reaction have been performed by using a four-dimensional rotating bond umbrella (RBU) model, based on a modified potential energy surface of Espinosa-Garcı́a and Corchado. The new surface gives a vibrationally adiabatic ground state barrier height of 14.1 kcal/mol. Calculated thermal rate constants are in good agreement with the experimental results. At room temperature the rate constant obtained is 8.16×10−19 cm3 molec−1 s−1. It is found that the simple energy minimization approximation gives significantly small thermal rate constants for this reaction.