The branching ratio of the O(1D) + HD reaction: A dynamical study

The isotopic branching on the reaction of O(1D) + HD has been the subject of several theoretical and experimental studies with results ranging from 1 to 2 for the OD/OH product ratio. We present a study of the dynamics of this reaction using a double-valued potential energy surface for the ground state water molecule. Our results predict a branching ratio close to 2 for this reaction in agreement with statistical studies but in contrast with experiment. This result can be attributed to the formation and dynamics of the intermediate complex.