Description of unimolecular reaction rates of Lennard-Jones clusters

Abstract

The unimolecular rate constant of Lennard-Jones clusters with N=54−56 atoms has been investigated in constant energy molecular dynamics simulations and compared with the detailed balance predictions. Decays were found to be statistical and absolute rate constants agree quantitatively with detailed balance predictions. The level densities required for the comparison of simulated and calculated rate constants were obtained from separate simulations using the integrated microcanonical temperature. The quantitative agreement between simulations and theory requires that the classical degeneracy of the ground state is included into the level densities.