Validation of a glue-model approach in a tight-binding hard-sphere model for hot fluid metals

Abstract

We have calculated thermodynamic, structural, and electronic properties of a model fluid of monovalent atoms which interact via hard-sphere repulsions and an attraction arising from the delocalization free energy of the valence electrons. These properties result from self-consistent Monte Carlo simulations of equilibrium ionic structures based, at each step in which an ion is to be moved, on the exact electronic free energies corresponding to the ionic configurations. The electronic energy is derived from a tight-binding model with electronic hopping which decays exponentially with distance. The liquid-vapor coexistence curve and both ionic and electronic structures are obtained. By direct comparisons, the present results confirm previous ones which were obtained basing the simulations on a glue-model description of ion energies. The importance of this confirmation is the validation of the glue-model approach, one of the few computational simplifications possible for realistic metallic fluids.