Lattice dynamics of the fullerenes M(x)C60 - art. no. 085407

Lattice dynamical calculations of the phonon density of states of external modes are reported for K3C60, Rb3C60, and Rb6C60 using three different mode ls of transferable interatomic potentials. On comparison with the experimen tal reported data, an interatomic potential consisting of Coulomb and short range interactions has been found most suitable to explain the phonon dens ity of states of the systems studied. Calculations using the rigid molecula r ion model have enabled assignment of various important features in the ex perimental phonon spectra in terms of the vibrations of different species.