Unified Analytical Formulae of Second Virial Coefficient with Kihara Potential and its Application to Real Gases

We propose a general evaluation method to calculate the second virial coefficient with Kihara potential (spherical core). The suggested approach is based on exponential function series expansion formula and gamma functions, which enable us to have accurate evaluation of the second virial coefficient. The results of second virial coefficient determined from Kihara potential are compared with the calculations of second virial coefficient with Lennard- Jones (12-6) potential. The analytical formula allows an accurate determination of Boyle temperature of gases. The accuracy of the obtained formula is tested by its application to gases Ar, Kr, Ne, CH4, C6H6, C3H8, n-C4H10, and n-C5H12. The results of the second virial coefficient in a wide temperature range and Boyle temperature are in good agreement with the data available in the literature.