RAMAN-SCATTERING AND INFRARED-ABSORPTION INTENSITIES OF FULLERENES FROM THE BOND CHARGE MODEL

A transferable version of the bond charge model (BCM), suitable to treat sp(2) configurations like fullerenes and graphite, has been extended to the calculation of Raman and infrared spectral intensities. The cluster polarizability has been derived consistently with the model. No additional parameter, besides the model parameters entering the dynamical matrix is required. Through its simple modelling of electron-phonon interaction, the model shows an excellent agreement with the experimental spectral intensities of C-60. The method allows for an unambiguous assignment of the theoretical frequencies to the experimental peaks in more complex systems such as C-70.