Department of Chemistry, Shiraz University, Shiraz, I.R. IRAN
The virial coefficients can be obtained from statistical mechanics in connection with the intermolecular potentials. The intermolecular potential of polyatomic molecules is usually assumed to consist of a spherically symmetric component plus a contribution due to asphericaity of the molecular charge distribution. In this study, the second virial coefficients have been calculated for N2, CO and SF6 from the Lennard-Jones (6-12) potential. The results are in good agreement with those obtained experimentally.