He adsorption and intercalation in ${\mathrm{C}}_{60}$ fullerite crystals

We calculate the interaction of a single helium atom with the low-temperature, orientationally ordered, simple cubic phase of a ${\mathrm{C}}_{60}$ fullerite crystal using anisotropic, helium-carbon pair potentials. The results of our study predict that helium is readily bound to sites on or near the surface of the fullerite crystal, but that intercalation of helium to the interior of the crystal at low temperatures is minimal due to the large energy barriers separating sites of octahedral and tetrahedral coordination.