Dynamics of a barrierless reaction on a two-dimensional potential surface in solution

Abstract

Numerical calculations on the dynamics of a barrierless reaction on a two-dimensional reaction potential surface is presented. We find that the second dimension can be rather important in the dynamics of a barrierless reaction. Especially, it can give rise to interesting dynamical behaviour such as the non-exponential decay of the population and a fractional viscosity dependence of the rate of non-radiative relaxation. One-dimensional behaviour is recovered not only when the frequency of one of the surfaces becomes much larger than that of the other, but also when the solvent friction along one dimension becomes very large. Thus, the concept of a reaction coordinate can be rather ambiguous in a multidimensional barrierless reaction.