Stochastic Model for a Fluid of Hard Cubes with Attractive Potential

A Monte Carlo computer study of a fluid, consisting of hard cubes not limited to only lattice sites, and with a square well attractive potential, is undertaken with the help of the ``Stochastic models'' method. Thus two parameters, fixing the transition probabilities, are used to produce arrays of the molecules of desired density and degree of clustering, while the method's variation principle enables the choice of the ``best'' configurations for given N, P, and T. The results strongly suggest the existence of a gas—liquid phase transition, yielding what appears to be a correct estimate of the critical pressure and temperature.