Equation of state for hard Gaussian overlap fluids

Abstract

The thermodynamic properties of hard Gaussian overlap fluids have been studied by computer simulation using constant-pressure Monte Carlo techniques for various molecular elongations κ in the range 3⩽κ⩽15. The work reported here concentrates on the equation of state and the Helmholtz free energy for the isotropic and nematic phases. Several theoretical approaches, based on the decoupling approximation, are considered and their predictions are compared with the simulation results. According to our results, none of these approximations yields a fully satisfactory description of the isotropic phase. In the nematic phase, the simple Parsons–Lee approximation is the only approach that yields results in quantitative agreement with simulation data for all elongations.