THE JAHN-TELLER INSTABILITY OF THE NEGATIVELY CHARGED C-60 MOLECULES

The linear t x (E + T) Jahn-Teller problem is relevant to the instabil ity of C-60 molecules in threefold degenerate states when the E and T modes become degenerate. An isostationary function method is generaliz ed to identify a;ll extremes on the corresponding potential energy sur face for different occupation numbers. For the C-60 molecules, the ext remes are found to form an equipotential minimal energy trough for all occupation cases. For a nondegenerate case, two different coupling re gimes are possible, favoring either pure tetragonal or pure trigonal d istortions, depending upon the correponding Jahn-Teller energies.