A new thermodynamic model for the hard-core fluid with a Yukawa tail

A new and analytical thermodynamic model for simple fluids with an intermolecular pair potential consisting of a hard-sphere core and an attractive Yukawa tail is presented. The model yields simple analytic expressions for all thermodynamic properties of the fluid system. The self-consistent numerical results of the present model for the compressibility factor, internal energy, and Helmholtz free energy are in excellent agreement with the Monte Carlo ‘‘experiments’’ for the whole range of temperatures and densities in which experimental data are available.