Spatially Mapping the Spectral Density of a SingleC60Molecule

We have used scanning tunneling spectroscopy to spatially map the energy-resolved local density of states of individual ${\mathrm{C}}_{\mathrm{60}}$ molecules on the Ag(100) surface. Spectral maps were obtained for molecular states derived from the ${\mathrm{C}}_{\mathrm{60}}$ HOMO, LUMO, and $\mathrm{L}\mathrm{U}\mathrm{M}\mathrm{O}+1$ orbitals, revealing new details of the spatially inhomogeneous ${\mathrm{C}}_{\mathrm{60}}$ local electronic structure. Spatial inhomogeneities are explained using ab initio pseudopotential density functional calculations. These calculations emphasize the need for explicitly including the ${\mathrm{C}}_{\mathrm{60}}\mathrm{\text{−}}\mathrm{A}\mathrm{g}$ interaction and STM tip trajectory to understand the observed ${\mathrm{C}}_{\mathrm{60}}$ local electronic structure.