van der Waals theory on the supercooled liquids of inverse-power potentials

Abstract

By solving a self-consistent integral equation numerically, we have obtained the equations-of-state and thermodynamic properties of equilibrium supercooled liquids with soft-sphere potentials plus the Kac potential (generalized van der Waals model). The equations of state obtained deviate from those of molecular-dynamics simulations below the liquid-glass transition predicted. The static pair structures differ significantly along two branches, i.e., molecular-dynamics glasses and equilibrium supercooled liquids. From entropy curves obtained from the solutions of integral equations, we indicate the stability limit of the equilibrium supercooled liquid for the softness parameter n=4, 6, 9, 12, and ∞. We also discuss the effect of the softness on the thermodynamic properties of supercooled liquids.