Coherent stimulated x-ray Raman spectroscopy: Attosecond extension of resonant inelastic x-ray Raman scattering

Spontaneous and stimulated resonant inelastic x-ray Raman-scattering signals are calculated using the Keldysh-Schwinger closed-time path loop and expressed as overlaps of doorway and window electron-hole wave packets. These are recast in terms of the one-particle Green's functions and expansion coefficients of configuration-interaction singles for valence excitations, which can be obtained from standard electronic structure codes. Calculation for many-body states of ground and core-excited systems is avoided.