On low-frequency phonons in C/sub 60/ and A/sub 3/C/sub 60/

Summary form only given. Recent inelastic neutron and specific heat data of fullerides and fullerene are analyzed in various anharmonic models. A consistent description of these data leads to the picture of strongly anharmonic octahedral potassium vibrations in K/sub 3/C/sub 60/ and weak anharmonicities of librons in fullerene and fullerides. In particular, the anomaly near 3meV seen at low temperatures in K/sub 3/C/sub 60/ can be explained by a pure lattice model and is probably not related to the occurence of superconductivity as suggested in [1]. The experimental thermal factors have been used to extract weak anharmonic shallow potential for librons. The temperature dependence of the form constants of C/sub 60/ obtained in such a way is an order of magnitude smaller compared with those of the commonly used pseudoharmonic approximation. Lifetime effects of librons due to interaction with high-frequency onball-modes are considered, too. We discuss also the role of these modes for the superconductivity within the Eliashberg picture and the T-dependence of the resistivity.