A time-dependent quantum dynamics study of the H2+CH3→H+CH4 reaction

We present a time-dependent wave-packet propagation calculation for the H-2+CH3-->H+CH4 reaction in six degrees of freedom and for zero total angular momentum. Initial state selected reaction probabilities for different initial rotational-vibrational states are presented in this study. Excitation of the H-2 stretch enhances the reaction probability, whereas the excitation of the CH3 umbrella mode has the opposite effect. The cumulative reaction probability (CRP) is obtained by summing over initial-state-selected reaction probabilities. The energy-shift approximation to account for the contribution of degrees of freedom missing in the six-dimensional calculation is employed to obtain an approximate full-dimensional CRP. Thermal rate constant is compared with different experiment results.