VIBRATIONAL-SPECTRUM OF C-60 - A BOND-CHARGE MODEL CALCULATION

We present a calculation of the vibrational spectrum of the C60 cluster by means of an adiabatic bond-charge model, which is directly derived from a calculation reproducing the intralayer phonons in crystalline graphite. Despite the very restricted number of adjustable parameters (four), the fourteen experimental Raman and infrared-active frequencies are reproduced within 3.0% (mean-square relative deviation). Good agreement is found also for other optically inactive modes, recently detected by neutron scattering and reflection electron energy loss spectroscopy.