The rotational dynamics of solid C-60 has been investigated experiment
ally by means of inelastic and quasielastic neutron scattering and the
oretically by lattice dynamical calculations (for the ordered phase) a
nd molecular dynamics calculations (for the disordered phase). Our res
ults provide evidence that the split-bond charge model fitted to the d
ata of the ordered phase gives also a good account of the rotational p
otential in the disordered phase.