Molecular thermodynamics on the basis of an equation of state for argon. I. Pure fluids of weakly nonspherical molecules

Abstract Using a recently published equation of state for argon as a basis, a molecular theory is developed for fluids composed of simple rigid molecules. Perturbation theory is used to incorporate the dominant long-range forces from quantum-mechanical perturbation theory, including nonadditive three-body induction forces. Anisotropic short-range forces are taken into account by a site—site interaction model for linear molecules, which is included with the perturbation treatment. Numerous calculations and comparisons with experimental data for pure fluids along the saturation curve and in the dense homogeneous fluid range serve to indicate the power of the present theory.