Optimal control approach to suppression of radiationless transitions

A general approach for eliminating radiationless transitions (RT) in polyatomic molecules is proposed. The approach is a combination of optimal control theory and electronically localized eigenstates of strongly vibronically coupled systems, to populate a superposition state that is immune to nonradiative decay. It is found that in the spectra of systems undergoing RT, the transition of the spectrum from regular to irregular at the interaction energy is a general phenomenon. The results show that most eigenstates are of strongly mixed character, above the intersection energy, but eigenstates of essentially pure character are found at all energies above E_c.