Resonance-Coupling Model for Simple Molecular Reactions

A strong-coupling model for the simple exchange reaction $A+BC\to AB+C$ is developed by considering the atom-diatom inelastic problems $A+BC$ and $AB+C$ separately and then introducing coupling between these configurations to allow for reaction. The inelastic systems are developed in the form of self-coupled differential-integral equations and are recoupled by the matrix element over internal states of the resonance energy between the adiabatic surfaces for the separate configurations. The model is applied to the D + ${\mathrm{H}}_2$ → DH + H system and its isotopes in a two-level approximation. At the threshold energy (0.33 eV) for the D + ${\mathrm{H}}_2$ → DH + H system, the calculated reactive total cross section is 1.62 ${\mathrm{\AA }}^2$ and the DH product is backscattered in the center-of-mass system.