Statistical rate theory for transient chemical species: classical lifetimes from periodic orbits

Abstract

The classical decay dynamics of extremely short-lived species is studied as a phase space process using an approach based on concepts from nonlinear dynamics. When the relaxation rate within the complex region is comparable to the reaction rate, it is found that ensembles of trajectories started in the complex region tend to a fractal asymptotic distribution which can be quite different from the expected microcanonical distribution. A systematically improvable statistical theory is formulated from the Lyapunov numbers of unstable periodic orbits which gives the decay rates to high accuracy.