Thermodynamic Properties of Ga sub(27)Si sub(3) Cluster Using Density Functional Molecular Dynamics

Density functional molecular dynamical calculations have been carried out to explore the effect of silicon impurities on thermodynamic properties of Ga sub(30). We have obtained 500 distinct low energy equilibrium geometries of Ga sub(27)Si sub(3) in order to obtain reliable ground state geometry. The specific heat has been calculated using multiple histogram techniques and compared with that of Ga sub(30). We demonstrate that silicon impurities have a dramatic effect on the thermodynamic properties of the host cluster. In contrast to Ga sub(30), the specific heat of Ga sub(27)Si sub(3) shows a clear melting peak at approximately 500 K, changing the character of Ga sub(30) from a nonmelter to a melter.