Augmented van der Waals equation of state for the Lennard-Jones fluid

Starting from a modified Carnahan–Starling expression for the pressure of a reference fluid of particles interacting just via the repulsive part of the Lennard-Jones (LJ) interaction, an augmented van der Waals type of equation of state is presented for the LJ fluid where the attractive part of the interaction enters via the second virial coefficient. The expression for the pressure is compared with empirical equations of state based on computer simulation data. A surprisingly good agreement is found over a large range of temperatures and densities. In the two-phase region, a slight additional modification is needed.