The CVS-uS, however, does not capture all the channels involving the dominant configuration when Ψ g ∼ Φ a i is an EOM-EE-CCSD state (first two channels in part (iii)). Unless enhanced by near-resonance consideration, these terms are small due to the small coefficients of the non-dominant COVV configurations in Ψ f with which the dominant OV configurations in Ψ g couple. Further, when ω is an X-ray frequency, the near-resonance conditions in these