Retension of the bridge diagrams in the pair-distribution function's integral equation

Abstract

A convenient theoretical method for calculating the structure properties of a homogeneous fluid, retaining the bridge diagrams, is developed. Using the diagrammatic expansion theory, the exact pair-distribution function's integral equation is reduced to a hypernetted chain-like equation in which the interaction between particles is replaced by an effective pair potential depending on the bridge function. The bridge diagrams are classified according to their number of field points. The contributions of these different diagrams are analyzed and an approximation for the bridge function is proposed.