  Optical absorption spectra of higher fullerenes (C70 and C76) as well as of
C60 are calculated by a tight binding model with a long range Coulomb
interaction. A reasonable parameter set gives calculated spectra which are in
overall agreement with the experiments of of C60 and C76 in solutions. The
variations of the spectral shape are discussed relating with the symmetry
reduction going from C60 and C70 to C76: the optical gap decreases and the
spectra have more small structures in the dependences on the excitation energy.
Keywords: optical absorption, fullerene, C60, C70, C76, CI calculation, theory

Condensed Matter;Chemical Physics