DENSITY-FUNCTIONAL THEORY AND THE ASYMPTOTIC HIGH-DENSITY EXPANSION OF THE FREE-ENERGY OF CLASSICAL SOLIDS AND FLUIDS

On the basis of the fundamental-measure free energy functional for har d spheres and thermodynamic perturbation theory, a unified analytical description of classical bulk solids and fluids is obtained, predictin g correctly the major features of their equations of state and freezin g parameters as obtained by simulations. The fundamentally different f luid and solid asymptotic high density expansions for the potential en ergy, featuring a static-lattice Madelung term and the harmonic 3/2k(B )T correction, on one hand, and a fluid Madelung energy with a similar to T-3/5 thermal energy correction, on the other, both originate from the same singularity in the hard sphere free energy functional.