Probing valence electronic wave-packet dynamics by all x-ray stimulated Raman spectroscopy: A simulation study

The femtosecond impulsive stimulated x-ray Raman signal from quinolinol is simulated and analyzed using the doorway-window representation of pump-probe spectroscopy. A valence electronic wave packet prepared by the pump, tuned on resonance with a given core hole, is localized in the vicinity of a selected atom and probed by a window localized on a different atom, selected by the probe pulse. All valence electronic states within the pulse bandwidths can be observed with high spatial and temporal resolution by monitoring the variation of the signal with the delay between the pulses. Natural orbital representation of the reduced single-electron density matrix is used to visualize the dynamics of the valence wave packet, described as a linear combination of determinants made of occupied and unoccupied Kohn-Sham orbitals.