Phase space prediction of product branching ratios: canonical competitive nonstatistical model

A new model is described for predicting branching ratios of chemical reactions when a branching of the reaction path occurs after the dynamical bottleneck, including the case where it occurs after an intermediate. The new model is based on combining nonstatistical phase space theory for the direct component of a reaction with variational transition-state theory for an indirect component of reaction and the competition between direct and indirect processes is treated by the unified statistical model.