A comparison of perturbative schemes and integral equation theories with computer simulations for fluids at high pressures

Abstract

We test some refined perturbation and integral equations theories for predicting the equilibrium properties of spherical fluids, with nonstandard interactions at high densities and temperatures. The perturbation theories are fast and convenient to use and give good results for the thermodynamic properties, but not for the structure. The integral equations require more computer time, but yield thermodynamics and structure that are in very good agreement with simulations. In fact there appears to be no need for computer simulations of classical systems of particles interacting with spherical potentials in the fluid regime—at least away from transitions.