Reformulation of the site-site interaction theory for molecular fluids

Abstract

Using graphical expansion theory, we show that the pair distribution function (PDF) of a molecular fluid may be related in a simple way to the PDF of a simple fluid having the same density as the system under consideration. An approximation for the exact expansion is proposed. The numerical calculations required by the present treatment are very easy to perform and lead to results in good agreement with those obtained by Monte Carlo simulation.