Resonant Inelastic X-Ray Scattering and Non Resonant X-ray Emission Spectra from Coupled-Cluster (Damped) Response Theory

A coupled cluster protocol rooted in damped response theory is presented for computing Resonant Inelastic X-Ray Scattering spectra of molecules in gas-phase. Working equations are reported for both linear (i.e., equation-of-motion) and non-linearparametrizations of the coupled-cluster wavefunction response. A simple scheme tocompute non-resonant X-ray emission spectra is also proposed. Illustrative results arepresented for water