Virial coefficients of hard-core attractive Yukawa fluids

Abstract

We used Mayer sampling technique—a method based on free energy perturbation, to calculate virial coefficients B 2– B 6 for hard-core Yukawa fluids with interaction range parameter, λ = 1.8, 3.0, 4.0, 5.0, 8.0, 9.0, and 10. We used these coefficients in the virial equation of state (VEOS) to obtain compressibility factor, Z, at super critical temperatures and found to be in excellent agreement with the predictions of equations of state based on mean spherical approximation (EOS-MSA) for Yukawa fluids up to a reduced density, ρ * , of 0.5. We inspected virial coefficients in representing the PVT behavior along the saturated vapor line of Yukawa fluids. VEOS4, VEOS5 and VEOS6 describe the PVT behavior along the saturated vapor line reasonably good for λ = 1.8, 3.0 and 4.0; and at higher λ, VEOS4 and VEOS5 represent the PVT behavior better than the series that includes B 6. We also report critical properties of Yukawa fluids based on VEOS and compared with the literature values.