Local compositions and the square-well fluid

Many applied thermodynamic models are based on the local composition concept, that is, that the composition of neighboring molecules around a central molecule is different from the bulk fluid composition. In this paper we consider the rigorous calculation of local compositions for a model mixture of squarewell molecules via statistical mechanics using Monte Carlo simulations and integral equation theory. The results show that the currently available models do not correctly describe the density and composition dependence of the local structure.Paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A.