DERIVATION OF THE PHASE FACTOR AND GEOMETRICAL PHASE FOR AN N-STATE DEGENERATE SYSTEM

This work considers the case of degenerate vibronic coupling of N stat es all at one single;point. For this case we first derived the extende d Single-state Born-Oppenheimer equation [M. Baer and R. Englman, Chem . Phys. Lett. 265, 105 (1997)] and then showed that such a system, Lik e the two-state system, can be described in terms of a single phase fa ctor and is characterized by a well-defined geometrical phase. (C) 199 8 American Institute of Physics.