S-matrix unitarization within reactive perturbation theory

Abstract

We explore the effect of S-matrix unitarization within the framework of reactive perturbation theory. Both exponential and Heitler based schemes are implemented for describing the dynamics on a pair of nonadiabatically coupled one-dimensional potential curves. Reflection and transmission probabilities are determined over a wide range of collision energies and for both low and high system masses. It is found that unitarization is an essential element in correctly describing energy trends in both nonreactive and reactive probabilities. Although exponentiation has been typically the unitarization method of choice, we find that the Heitler method has merit in its own right.