Perturbation theories for polar fluids

Abstract

The free energy of dense fluids with permanent dipoles is computed through the Monte Carlo method with two types of intermolecular interaction: Stockmayer potential and hard-sphere potential with an added dipolar interaction. A comparison is made with the Padé representation recently proposed by Stell which is shown to be good. In the case of hard spheres with permanent dipoles we propose another equally successful perturbation theory, which is based on a partial resummation of the mixed perturbation theory first introduced by Lebowitz, Stell, and Baer. This perturbation theory is then applied to the general case of an interaction composed of a spherically symmetric two-body potential with permanent dipoles.