MODIFIED PADE APPROXIMANTS AND EQUATION OF STATE

A modified Pade approximant is proposed for a resummation of the viral expansion. It includes the Carnahan-Starling equation of state as a s pecial case. The second Pade approximant is comparable in accuracy to the Carnahan-Starling formula, the Ree-Hoover [3,3] Pade approximant, and the computer simulation results. A generalized Carnahan-Starling f ormula is then obtained for the equation of state for the Lennard-Jone s fluid by using the modified Pade approximant summing the viral expan sion. The generalized Carnahan-Starling formula is comparable with com puter simulation results and the Song-Mason equation of state down to the critical temperature, but its accuracy deteriorates below the crit ical temperature.