Timescale of isomerization reactions and isotropic inflation model of basin boundaries in cluster dynamics

We present a theoretical treatment that accounts for the internal-energy dependence of the rate of geometrical isomerization of Ar₇-like clusters in the so-called liquid-like phase (high-energy region). Since many trajectories representing this reaction pass through a broad range of basin boundaries other than the transition state and since there are many channels involved, the reaction rate is not determined by a few local characteristics of the potential surfaces such as the transition state or the reaction coordinates. We therefore propose a reaction rate model which is based on the isotropic inflation of the density of states at the global basin boundaries.