On the nitrogen pair potential

A non-product integration algorithm is used to compute the second virial coefficient of a number of potential functions proposed for nitrogen. It is shown that corrections to the orientational variation of the dispersion interaction assumed by a diatomic Lennard-Jones potential have a larger effect upon the second virial coefficient than does the inclusion of the electrostatic quadrupole interaction. We derive a nitrogen pair potential which should be useful for future research. This pair potential takes the form of an atomatom potential but unlike the diatomic Lennard-Jones potential has non-spherical inter-atomic interactions which combine to produce the known asymptotic form of the long-range interaction of two nitrogen molecules.