This paper developed the conceptual model of symmetric extended Lennard-Jones fluid based on an extended Lennard-Jones potential function. Therein, important relationships between averaged intermolecular potential field (AIPF) and thermodynamic properties were presented, in which the equation of state was included. These formulascan not only predict the p-V-T properties of argon, nitrogen, carbon monoxide and methane that are representatives of spherical, polar and non-polar molecular fluids in acceptable accuracy, but also physically interpret...
