Electronic structure of solid ${\mathrm{C}}_{60}$: Experiment and theory

Synchrotron-radiation and x-ray photoemission studies of the valence states of condensed phase-pure ${\mathrm{C}}_{60}$ showed seventeen distinct molecular fetaures extending ∼23 eV below the highest occupied molecular states with intensity variations due to matrix-element effects involving both cluster and free-electron-like final states. Pseudopotential calculations established the orign of these features, and comparison with experiment was excellent. The sharp C 1s main line indicated a single species, and the nine satellite structures were due to shakeup and plasmon features. The 1.9-eV feature reflected transitions to the lowest unoccupied molecular level of the excited state.