estimation of second virial coefficients for rare gases in thermodynamic views

using the gaussian 2003 software and mp2/ 6–311 ++ g** method for he: he, ne:ne andmp2/6-31g method for ar: ar, kr: kr and hf/sto-3g method for xe: xe, the optimizedinteraction energies between two like atoms of rare gases (he, ne, ar, kr and xe) as a functionof the distances between the centers of two considered atoms were evaluated and the resultswere interpreted according to the lennard – jones equation . in addition, the second virialcoefficient of each rare gas was calculated upon the appropriate equations of statisticalthermodynamics. the resultent coefficients were comparable with those are available in theliterature.