3-BODY FORCES IN DENSE SYSTEMS

The contributions of long-range triple-dipole three-body interactions to the thermodynamic properties of dense gaseous argon are calculated using a recently developed perturbation theory together with an accurately determined pair potential function. Calculated pressures, internal energies, and critical constants are in reasonable agreement with experiment provided that the three-body contributions are included. The validity of the principle of corresponding states in the presence of three-body forces is discussed. © 1968 The American Physical Society.