On the dependence of the lifetime of an atomic cluster on the intensity of its heat exchange with the environment

The molecular dynamics and Monte Carlo studies of the thermal stability of C₂₀, C₃₆, and C₆₀ fullerenes and the methane molecule are reported. It has been shown that the heat transfer between the atomic cluster and the external heat reservoir can either promote or prohibit the formation of defects in this cluster. The wide temperature and pressure ranges have been determined where the defect formation rate is essentially non-Arrhenius. It has been shown that the lifetime of light clusters in molecules depends more strongly on the contact with the heat reservoir. A statistical model that is based on the kinetic equation and allows for an analytical solution has been developed to explain the results. Within this model, the generalized Arrhenius formula has been derived to predict the lifetime of the clusters in an arbitrary thermal contact with the environment.