Molecular interactions in fullerenes and equilibrium of higher fullerites C76 and C84 with their vapors

From simple topological considerations on the molecular shapes, a new method for calculating the coefficients of the Girifalco intermolecular potential for various fullerenes is proposed. This eliminates the necessity for fitting the coefficients to data of measurements for each specific fullerene. We calculate them for C76 and C84 and apply this potential to perform research on the equilibrium of these fullerites with their vapors. The temperature dependence of the lattice parameters, the saturated vapor pressures and the enthalpies of sublimation is studied. Results are in good agreement with available experimental data.