Pressure dependent study of the solid-solid phase change in 38-atom Lennard-Jones cluster.

Phase change phenomena in clusters are often modeled by augmenting physical interaction potentials with an external constraining potential to handle evaporation processes in finite temperature simulations. These external constraining potentials exert a pressure on the cluster. The influence of this constraining pressure on phase change phenomena in 38-atom Lennard-Jones clusters is investigated, and it is demonstrated that modest changes in the parameters of the constraining potential can lead to an order of magnitude change in the constraining pressure. At sufficiently high pressures the solid to solidlike phase change region in the 38-atom Lennard-Jones cluster is completely eliminated.