Thermodynamic Properties of Ga27Si3 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 Ga30. We have obtained 500 distinct low energy equilibrium geometries of Ga27Si3 in order to obtain reliable ground state geometry. The specific heat has been calculated using multiple histogram techniques and compared with that of Ga30. We demonstrate that silicon impurities have a dramatic effect on the thermodynamic properties of the host cluster. In contrast to Ga30, the specific heat of Ga27Si3 shows a clear melting peak at ≈500 K, changing the character of Ga30 from a nonmelter to a melter.