Semiclassical vibrationally adiabatic model for resonances in reactive collisions

A vibrationally adiabatic model is used to predict the positions of resonances in reactive scattering for collinear H + H₂, H + FH, and Cl + H₂ and isotopic analogues of these reactions and for three-dimensional H + H₂. We obtain good agreement with accurate quantum mechanical results for both shape and Feshbach resonances. In some cases the agreement is better if we assume that the system follows a dynamical path on which the internal centrifugal forces are balanced by the potential energy surface than if we assume that the system follows the minimum-energy path.