An improved intermolecular potential for nitrogen

Abstract

Using new ab initio calculations for the multipole and short range interactions and the results for the dispersion interactions recently calculated in our institute, we have constructed a new intermolecular potential for nitrogen. Its distance and angular dependence is expressed analytically in a spherical expansion. The long range dispersion interactions have been damped for charge penetration and exchange effects via the parameter-free damping functions of Tang and Toennies, generalized to the case of an anisotropic potential, and we have introduced two scaling constants in the short range repulsion in order to obtain a second virial coefficient that lies within the experimental error in the entire temperature range. The use of the new potential in lattice dynamics calculations yields good results for several properties of solid nitrogen.