Origin of the photoemission intensity oscillation of C60

The photon-energy dependences of photoemission intensities of C-60 were quantitatively calculated by the single-scattering approximation for the final state and the ab initio molecular orbital calculation for the initial state. The calculated results agreed well with the measured intensity oscillation in the photon-energy range of hv = 18-110 eV. The calculation by the plane-wave approximation for the final state also gave similar oscillations, which suggests that the oscillations are independent of the accuracy of the final state. These results indicated that the oscillations originate from the interference of photoelectron waves emanating from the 60 carbon atoms, i.e., the multicentered photoemission with the phase difference of each wave. Further, the analytical calculation with a simplified spherical-shell-like initial state revealed that the spherical structure of C-60 molecule and its large radius dominate the oscillations.