Electronic transport, structure, and energetics of endohedral Gd@C82 metallofullerenes

Electronic structure and transport properties of the fullerene C-82 and the metallofullerene Gd@C-82 are investigated with density functional theory and the Landauer-Buttiker formalism. The ground-state structure of Gd@C-82 is found to have the Gd atom below the C-C bond on the C-2 molecular axis of C-82. Insertion of Gd into C-82 deforms the carbon chain in the vicinity of the Gd atoms. Significant overlap of the electron distribution is found between Gd and the C-82 cage, with the transferred Gd electron density localized mainly on the nearest carbon atoms. This charge localization reduces some of the conducting channels for the transport, causing a reduction in the conductivity of the Gd@C-82 species relative to the empty C-82 molecule. The electron transport across the metallofullerene is found to be insensitive to the spin state of the Gd atom.