Orientational order and disorder in fullerene compounds

The rich variety of orientational order and disorder phenomena in fullerene -based solids is illustrated with the examples of pure C-60 and C-70, Of C- 60-tetraphenylphosphoniumbromide and of AC(60) (A = K, Rb), studied by X-ra y diffraction and diffuse scattering methods. The importance of the orienta tional phenomena with respect to the physical properties of these compounds is emphasized.