The site-site pair correlation functions of molecular fluids

Abstract

Calculations are performed using the RAM perturbation theory for heteronuclear hard-sphere diatomics, and compared with those obtained from RISM theory. Calculations are made to first order in the RAM theory employing three different intermolecular coordinate systems, as well using a mixture reference system suggested in part I of this series. The mixture reference system produces uniformly poor results. If a coordinate system is chosen in which reference points are placed at the molecular centres of mass, good results are obtained for all but the site-site distribution function of the smaller sphere.