Ten-Dimensional Quantum Dynamics Study of H+CH _3 D \rightarrow H _2 +CH _2 D Reaction

The mode selectivity of the H+CH _3 D \rightarrow H _2 +CH _2 D reaction was studied using a recently developed ten-dimensional time-dependent wave packet method. The reaction dynamics are studied for the reactant CH _3 D initially from the ground state, the CH _3 symmetry and asymmetry stretching excitation, the CD stretching excitation and the fundamental and the first overtone of the CH _3 bending mode. The calculated reaction probabilities show that exciting either of the CH _3 stretching modes enhances the reactivity in the collision energy range below 1.0 eV, while the CD stretching excitation does not obviously prompt the reaction. Fundamental CH _3 bending excitation has nearly no effect on promoting reactivity. However, a significant enhancement is observed for the first overtone excitation of the CH _3 bending mode, resulting from the Fermi resonance between the fundamental state of the CH _3 symmetry stretching mode and the first overtone state of the CH _3 bending mode.