NUCLEAR-DYNAMICS OF SEVERAL DECAYING OVERLAPPING ELECTRONIC STATES - A TIME-DEPENDENT FORMULATION

The nuclear dynamics accompanying the excitation of a polyatomic target to a manifold of decaying overlapping electronic states and the subsequent decay to final electronic states are discussed. Nonadiabatic interactions within the manifold of decaying states as well as of final states are included. The cross sections for the excitation and for the production of final states are derived. The wave packet dynamics are investigated for both the excitation and the decay and related to the corresponding cross sections. Particular attention is paid to core levels of systems with equivalent atoms. The time-dependent formulation is also used to compute the gross features of the observed spectra via a spectral moment expansion. An interesting example is investigated where the decaying as well as the final states have extremely localized electron vacancies.