Cherrypicking Resolvents: A General Strategy for Convergent Coupled-Cluster Damped Response Calculations of Core-Level Spectra

Damped response theory calculations within the higher-level coupled cluster methods such as EOM-CCSD are typically divergent in the X-ray regime due to the coupling of response states with the valence ionization continuum. We provide a novel strategy for convergent response calculations in the X-ray regime within the damped response EOM-CCSD framework that include contributions from both the core and valence states to the response.