Interfullerene Interaction and Properties of Fullerites

The correlation is revealed between the mass of a molecule of $\text{C}_{\text{cn}}$ fullerene and the properties of fcc-fullerites such as the sublimation energy, the distance between the centers of the nearest molecules, the Grüneisen parameter, bulk modulus at zero pressure and temperature. The data of correlation dependences are used to determine the parameters of the Mie-Lennard-Jones pair potential for interfullerene interaction in fcc-fullerites. The thus determined parameters of the potential are used to calculate the properties of fullerites and obtain good agreement with known literature data. It is demonstrated that, at $nc \le 15$ to $20$, crystals of $\text{C}_{\text{nc}}$ fullerites are unstable. At the same time, fullerites with $nc \ge 100$ will have anomalously low values of surface energy, and this must bring about the fragmentation of nanoclusters of $\text{C}_{\text{nc}}$ molecules this large. The parameters of the triple and critical points of fullerenes are estimated. A study is made of the evolution of the potential parameters and of the properties identified above with the variation of the molecular mass of fullerene.