On the theory of fluids

Abstract

The theory of fluids based on the radial distribution function, g(r) , is related to the direct correlation function, f(r) , of scattering theory. The simplest form of the Born-Green theory is shown to be intimately related to the first approximation to f(r) . The second approximation to f(r) is considered in detail, and shown to effect a considerable improvement on earlier theories. It leads to a critical point at which p/ρkT =⅓. Fournet’s application of the Born-Green theory to X-ray scattering by fluids is shown to be correct only to the first power in the density ρ. The terms in ρ and ρ 2 are considered in detail for the case of hard spheres.