In stark contrast, the results obtained with EA-CIS and EA-TDDFT (Fig. ) capture the pre-edge, main-edge, and postedge features with high fidelity. Interestingly, the rigid shift of the EA-TDDFT spectra that was chosen to align the pre-edge features to experiment (shift values in Tab. S1) is of similar magnitude to the shift that was required to align CCSD results for NH 3 and NH + 4 with experiment (about -2 eV). This suggests that the peak positions of EA-TDDFT are of similar quality to those predicted by CCSD and that EA-TDDFT still shows a remarkable improvement over methods like damped TDDFT (with a similar functional) which requires a shift of 15 eV for the O K-edge of liquid water. These improvements in both peak position and peak intensity suggest that orbital relaxation is the primary source of error in linear-response-based XAS calculations and that merely changing the initial reference from that of the n-electron ground state to the core-ionized n-1-electron determinant is sufficient to recover the entire spectrum without ever explicitly including double (or higher) excitations. The good agreement of EA-TDDFT with CCSD also implies that orbital relaxation is indeed the pri- mary role of double excitations in the core-excitation spectra of solvated chromophores.