Perturbation theory applied to the freezing of classical systems

Abstract

We analyze the density-functional perturbation theory for simple classical systems and in particular the application of the perturbation-weighted density approximation to the study of the solid-fluid coexistence. The main assumptions of the approximation are discussed to clarify the dependence of the results with the partition of the intermolecular potential into repulsive and attractive contributions. A simplified version of the theory is presented and the results for the phase diagram of a Lennard-Jones system are compared with other theories and computer simulations.