Low energy modes of metals in fullerene cages

Vibrations between carbon cage and Sc are discussed in the endohedral compo und SC2@C-84. The attention was concentrated to the region below 300 cm(-1) in which one expects this type of motions. Comparing Raman and far-infrare d spectra for empty and filled cages with the same symmetry we identified 9 modes for the Sc-cage vibrations. This large number of the modes will be d iscussed from a point of view of different mechanisms of splitting. We pres ent also temperature dependent measurements which suggest a possible order- disorder phase transition between 160 and 180K.