AB INITIO INSIGHT IN JAHN-TELLER AND PSEUDO JAHN-TELLER PROBLEMS

摘要

Ab initio methods proved to be most useful not only in accurate estimation of the vibronic coupling parameters in JT problems, but also in solution of more general problems of JT vibronic coupling. This conclusion is clearly demonstrated above in this paper by showing how ab initio methods allowed us to reveal the vibronic ground state that reversed a long standing erroneous paradigm, to accurately calculate PJT instabilities, and to correctly estimate the predominant role of the JT mode anharmonicity in forming the energy barrier between the equivalent minima of the APES in the E directX e problem.