NONRADIATIVE LIFETIMES FOR LIH IN THE A-STATE USING ADIABATIC AND DIABATIC SCHEMES

Accurate positions and nonradiative lifetimes of states belonging to t he adiabatic A state of LiH are estimated. The results coming from a G olden Rule treatment in the adiabatic scheme present excellent; agreem ent with those obtained through a diabatic close coupling calculation. That confirms the accuracy reached in both approaches and also in the treatment of the diabatic-adiabatic transformation. It involves, in p articular, an effective phase control that is needed to properly estim ate nonadiabatic couplings. Also, a powerful numerical procedure to ob tain energy profiles in the diabatic close coupling frame is described and applied in this work. (C) 1997 American Institute of Physics.