Core-hole effects in x-ray-absorption spectra of fullerenes

Near-edge x-ray-absorption fine-structure spectra of two fullerenes, ${\mathrm{C}}_{60}$ and ${\mathrm{C}}_{70},$ have been simulated by means of density-functional theory techniques using ground-state Kohn-Sham orbitals, transition state potentials, or full core-hole potentials. The very good experimental agreement obtained when the full core hole explicitly is taken into account gives an indication of significant excitonic effects for the x-ray-absorption spectra of fullerenes.