Size-temperature phase diagram for small Lennard-Jones clusters

The size-temperature phase diagram for small Lennard-Jones clusters LJ(n)(n <= 147) is constructed based on the analysis of the heat capacities C-nu(T), computed by the parallel tempering Monte Carlo method. Two types of phase transitions are often observed: the higher-temperature solid-liquid transition, due to melting of the cluster core, and the lower-temperature melting that occurs within the surface layer. The latter transition can only be observed for clusters with Mackay packing of the overlayer.