PNNL

Abstract

We investigate the electronic structure of an endohedral fullerene, Sc3N@C80, chemisorbed on Cu(110)-(2x1)-O surface by scanning tunneling microscopy and density-functional theory. Scanning tunneling microscopy and spectroscopy identify a series of delocalized atomlike superatom molecular orbitals (SAMOs) in the Sc3N@C80 and its aggregates. By contrast to C60, the encapsulated Sc3N cluster in Sc3N@C80 distorts the nearly-spherical central potential of the carbon cage, imparting an asymmetric spatial distribution to the SAMOs. When Sc3N@C80 molecules form dimers and trimers, however, the strong intermolecular hybridization results in highly symmetric hybridized SAMOs with clear bonding and antibonding characteristics. The electronic-structure calculations on Sc3N@C80 and its aggregates confirm the existence of SAMOs and reproduce their hybridization as observed in the experiment.