Role of the vibrational contribution in Coulomb explosion of dicationic neon gas clusters: a parallel tempering based study

Abstract

The problem of Coulomb explosion in dicationic neon gas clusters has been investigated with special emphasis on the role of the vibrational contribution. The problem has been handled by describing the dicationic neon gas system with an adequate potential energy surface comprising dispersive interaction, Coulombic and polarizability containing terms. This potential energy surface, if explored for various sizes of the clusters, shows Coulombic explosion features below a certain threshold size. However this classical treatment fails to account for the correct threshold predicted from other studies including experiments. This signifies that quantum effects play an important role. With the incorporation of the vibrational contribution as the quantum effect, it is seen that reduction in the threshold value indeed occurs and the amount of decrease significantly varies with temperature. The whole study has been done using the stochastic search strategy or parallel tempering to explore the potential energy surface of the system. The stochastic strategy guarantees the achievement of a low energy solution as it is not stuck in local energy basins.