Overall, the EA-CIS spectra are qualitatively similar to those predicted by EA-TDDFT, with the exception that an additional curiosity emerges in the spectrum of liquid water (Fig. ). Whereas EA-TDDFT predicts that the main-edge peak at ∼ 538 eV is the most intense, followed by a small shoulder at ∼ 539 eV and then a sizable post-edge peak at ∼ 542 eV, the EA-CIS spectrum injects most of the intensity into the post-edge feature, leaving the main-edge peak to be the second-lowest in intensity. This qualitative failure of EA-CIS emerges from a lack of explicit correlation effects in the core-ionized reference orbitals, and is likely a result of spectral compression such that higher-energy features are blending in with the highest-energy peak in the post-edge. Interestingly, liquid water is the only spectrum that contains such qualitative differences, but it is clear from Fig. -f that EA-CIS does exaggerate the intensities of high-energy features relative to EA-TDDFT and that the features do appear to be compressed relative to their counterparts in EA-TDDFT. Clearly orbital relaxation plays a more sizable role in the overall shape of a given spectrum, but correlation (or lack thereof) can also play a significant qualitative role in the spectral profile. In order to ensure that these arguments were not crafted atop the assumption of a Gaussian line shape, we have reproduced these conclusions by replotting each spectrum using weighted histograms (Fig. ) which forego any assumption about the spectral distribution.