IS X-RAY-ABSORPTION SPECTROSCOPY OF C-60 - THE EFFECTS OF SCREENING AND CORE-HOLE RELAXATION

The C 1s near-edge absorption spectrum of C60 has been studied experimentally and theoretically. An assignment of the C 1s transitions to unoccupied states below the continuum threshold is suggested on the basis of multiple-scattering Xα local density and semiempirical intermediate-neglect-of-differential-overlap self-consistent-field calculations, including effects of screening and relaxation of the symmetry-breaking core hole. The present work shows that modeling the core hole is necessary for understanding the absorption spectrum of C60. Thus excitonic interactions between the excited electron and the core hole left behind give a final state that is significantly different from the ground state. © 1994 The American Physical Society.