The generalized van der Waals partition function. III. Local composition models for a mixture of equal size square-well molecules

Abstract

New local composition models for mixtures of equal size molecules with differing attractive forces are presented, and compared with our results of Monte Carlo computer simulations for mixtures of square-well molecules which are also reported here. Unlike most previous local composition models, these new models predict random mixing in the high density limit and Boltzmann factor nonrandomness at low density; both limiting behaviors are in agreement with statistical mechanical theory. The predictions of these new models as a function of composition, density and temperature are in good agreement with the Monte Carlo computer simulation results.