Melting of free copper clusters

Extensive molecular-dynamics simulations of melting processes of copper clu sters, Cu-55, Cu-147 and Cu-309 with closed-shell icosahedral structure, we re performed using an environment-dependent classical tight-binding potenti al. The results reveal that the cluster may transit completely from pure so lid to pure liquid phase with temperature via a dynamics-coexistence (DC) p rocess, depending upon the latent heat and vibrational entropy. In the DC r egime, no other than the first-order solid-liquid phase transition with tim e is related to the specific structure of the cluster.