Nonradiative lifetimes for LiH in the A state using adiabatic and diabatic schemes

Accurate positions and nonradiative lifetimes of states belonging to the adiabatic A state of LiH are estimated. The results coming from a Golden Rule treatment in the adiabatic scheme present excellent; agreement 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 particular, an effective phase control that is needed to properly estimate nonadiabatic couplings. Also, a powerful numerical procedure to obtain energy profiles in the diabatic close coupling frame is described and applied in this work. (C) 1997 American Institute of Physics.