Comparison of electron gas and a b i n i t i o potentials for the N2–N2 interactions. Application in the second virial coefficient

Abstract

A detailed potential for the interaction between two rigid N₂ molecules is given in the form of a spherical expansion. The interaction energy is found as the sum of the so‐called Hartree–Fock part of the electron gas expression including the Rae correction and the ’’ab initio’’ dispersion energy in the multipole expansion. Potential surface cuts computed with this expansion agree to a large extent with a similar potential completely based on ab initio calculations. Comparison of the experimental second virial coefficient curve with the curves obtained from a four dimensional quadrature using both ab initio and electron gas potentials demonstrates the usefulness of these potentials, and underlines the importance of the anisotropic contributions.