Fullerene in a metal-organic matrix: design of the electronic structure.

We present a theoretical study of a new hybrid compound, where the C60 molecules are encapsulated in a recently discovered metal-organic framework (MOF). Being placed in a rigid skeleton, the fullerene molecules form a cubic crystal, while the intermolecular distance of the fullerenes is tuned by the choice of appropriate organic linkers of the MOF structure. The resulting C60 crystal shows a density of conduction states considerably higher than any of the fullerene crystals considered so far, which is a key factor influencing the transition temperature of the superconducting state. This constitutes a new approach of tuning the density of states of a fullerene crystal.