Determination and Assessment of Morse Potential Functions for some Nonpolar Gases

Morse potential functions for Ar, Kr, Xe, N2, and CH4 are determined from the experimental viscosity, η(T), and second virial coefficient, B(T). These potentials afford only conditionally compatible (and not very accurate) descriptions of these two properties, although they compare favorably with high-energy repulsive potentials. In these respects, they are superior to those based largely on crystal data. The Morse and the Kihara spherical-core potentials for Ar are compared. Neither is able to reproduce the known B(T), η(T) as well as the repulsive potentials within acceptable limits.