The electronic spectroscopy of C60 and C70: a theoretical study

The electronic absorption spectra of C60 and C70 are simulated with the help of semiempirical quantum-chemical calculations. It is shown that the main features observed experimentally are satisfactorily reproduced by the calculations. Double-excited configurations are necessary to correctly describe the lowest excited states of C70 and dipole-allowed excited states are computed to be very close to the lowest excited state S1. Preliminary results on the simulation of the fluorescence spectrum of C70 are discussed. (orig.)