The effect of the symmetric and asymmetric stretching vibrations of CH4 onthe O(P-3)+CH4 -> OH+CH3 reaction

We present a four-dimensional quantum scattering model to treat reactions o f the type CH4+X --> CH3+XH. The most important feature of the model is tha t it allows the effect of the symmetric and asymmetric stretching vibration s of CH4 on reactivity to be studied. We used the model to study the CH4+O( P-3)--> CH3+OH reaction. We found that the symmetric stretch vibration is m ore efficient in promoting reaction than the asymmetric stretch. We also fo und that exciting any of these stretching modes produces an inverted popula tion in the umbrella vibration of product CH3 while, for the reactants in t he ground state, the population is non-inverted.