Square-well fluid based decoupling approximation for system of hard non-spherical particles with spherical square-wells

Abstract

A new theory based on the virial equation has been developed to study a system of hard non-spherical particles embedded into square-wells. The theory relies on a mapping of the pair correlation function of the system of interest onto that of spherical square-wells. This is a generalization of the Parsons—Lee theory of pure hard convex bodies. Comparisons show that this theory is superior to previous theories and incorporates them into a common framework. Competition between the excluded volume effect of repulsive forces and the condensation effect of attractive forces has been demonstrated. We have found three types of phase diagrams, among which one exhibits a nematic—nematic phase transition.