Third virial coefficient for the kihara, exp-6, and square-well potentials

Abstract

The classical third virial coefficient, assuming pairwise additivity, has been calculated by numerical integration for the Kihara and exp-6 potential functions. The nonadditive contribution, using the three-body potential model of Midzuno and Kihara (modified in the case of nonsixth-power attraction) has also been calculated numerically for the Kihara, exp-6, and square-well potentials. Results are tabulated for each potential model at 40 reduced temperatures from 0.50 to 100.0 and for a range of third parameter values. A comparison is made of the change in emphasis on intermolecular separation between the second and third virial coefficients.