Ab InitioIntermolecular Potential of SolidC60in the Low-Temperature Phase

We present ab initio calculations for the intermolecular potential of ${\mathrm{C}}_{60}$ in the low-temperature $\mathrm{Pa}\overline{3}$ structure as function of both the rotation angle and the lattice constant. These investigations are based on density-functional total-energy studies in the framework of the local-density approximation (LDA). The zero pressure ground-state phase, selected Raman frequencies, and the equation of state are determined in agreement with experimental data. These results show that despite their well-known deficiencies, LDA calculations are able to properly describe the angular and distance dependence of the intermolecular potential for ${\mathrm{C}}_{60}$ thus emphasizing the importance of short-range chemical bonding in the $\mathrm{Pa}\overline{3}$ phase.