Nonadiabatic Dynamics Studies for the H + CaH ( v = 0, j = 0) Reaction

The nonadiabatic dynamics studies of the Ca( 1 S)/Ca( 1 P) + H 2 abstraction channel and H + CaH' exchange channel were performed in the collision energy range from 0 to 1.0 eV. To clarify the nonadiabatic effects, present nonadiabatic results were compared with previous adiabatic results. Nonadiabatic effects can significantly alter the competition mechanism between the abstraction and exchange reaction channels. Specifically, for the abstraction channel at high collision energies, the adiabatic reaction probability is considerably larger than the nonadiabatic counterpart, whereas for the exchange channel the opposite trend holds: the adiabatic probability is markedly smaller than the nonadiabatic one. The influence of nonadiabatic effects on integral cross sections is similar to that on reaction probabilities. Furthermore, these effects also significantly affect the vibrational and rotational state distributions of products, especially when the vibrational quantum number is small.