Equation of state for the Lennard–Jones fluid based on the perturbation theory

An easy-to-use equation of state for the Lennard–Jones fluid based on the Barker and Henderson perturbation theory is presented. The model uses the hard sphere as the reference fluid, with its properties described using the Carnahan–Starling equation of state and a shell approach to describe the radial distribution function. The contributions of first and second order terms in the perturbation series were calculated using molecular simulation and are compared with the proposed EoS. The equation presented is in good agreement with the molecular simulation data for the pressure and internal energy of the Lennard–Jones fluid. As the equation is based on the perturbation theory it over predicts the critical temperature found from molecular simulation.