COOPERATIVE JAHN-TELLER EFFECT AND THE BAND STRUCTURES OF KXC60 CRYSTALS

Band reconstructions upon doping are studied with the use of a general ized version of the Su-Shrieffer-Heeger model for the intermolecular a nd intramolecular degrees of freedom. A simple model describing the co valent bond formation in C-60 compounds is proposed. Electron charge d istributions over the molecular surface and Jahn-Teller distortions of carbon atoms in C-60 are calculated self-consistently for linear C-60 polymer and C-60(-) polyanion chains. It is shown that the polymeriza tion of equally oriented C-60 molecules under phase transitions may be caused by the cooperative Jahn-Teller effect.