Stimulated X-ray Raman Imaging of Conical Intersections.

The conical intersection dynamics of thiophenol is studied theoretically using the stimulated X-ray Raman imaging (SXRI) technique. SXRI employs a hard X-ray narrowband/broadband hybrid probe field and provides a real-time and real-space image of the passage through conical intersections. The signal, calculated using the minimal-coupling radiation/matter Hamiltonian, carries the phase information, and the real-space image of the transition charge density can be reconstructed by its Fourier transform. The two conical intersections (S2/S1 (11ππ*/1πσ*) and S1/S0 (1πσ*/S0)) can be distinguished and identified by the diffraction patterns in the level crossing regimes.