Solid nitrogen: structural implications of non-additive three-body interactions

Abstract The non-additive triple-dipole contributions to the lattice energy of nitrogen in the α, β and γ phases have been calculated, using Stogryn's expression for the triple-dipole energy of non-spherical molecules. Near to the low-temperature α-γ transition and to the low-pressure α-β transition, the triple-dipole energy is a substantial fraction of the total lattice energy, but does not change significantly across the transitions. We conclude that these contributions will not significantly affect the positions of the phase transitions.