The bridge function for hard spheres

Abstract

The paper presents an empirical formula for expressing the bridge function (the sum of elementary graphs) in terms of the interparticle separation and the density. The formulae is fully consistent with the best computer-simulation thermodynamic and structural data for hard spheres in the fluid region. It can serve as both a direct and convenient testing ground for the integral-equation theories of hard spheres and an input to the reference-hypernetted chain approximation for simple fluids.