In order to establish the characteristic level of accuracy offered by the EOM-CCSD and EOM-CCSD* methods prior to embedding, we computed the C, N, O, and F core binding energies at K-edge for the molecules in the core65 dataset. 37 This dataset is composed of small to moderate-sized organic molecules. The geometries of these molecules were taken from Ref. 37.The absolute core-ionization values for each molecule and the corresponding experimental references are comprehensively presented in Table .