When a calculation of just the elemental K-edge is desired (and not any higher-lying states), then ∆SCF procedure is usually straightforward and ∆SCF results therefore serve as a baseline for evaluating methods that are based on Kohn-Sham eigenvalues. At the ∆SCF level, several functionals afford results within ∼ 0.3 eV of experiment, when atomic relativistic corrections are included as described in Section 3. These functionals include SCAN, SCAN0, and B3LYP, whereas BH&HLYP, CAM-B3LYP, and ωB97X-V afford slightly larger errors but still exhibit MAEs below 0.5 eV. Interestingly, the SRC1-r1 functional affords the largest errors (MAE = 1.1 eV), despite having been parameterized for TD-DFT calculations of K-edge transitions for these same secondrow elements. Clearly, cancellation of some other errors in TD-DFT is folded into the parameterization of this functional. We previously observed that SRC1-r1 also affords poor results for ∆SCF calculations of Kshell electron binding energies, with a MAE of 1.5 eV as compared to 0.2 eV for functionals such as SCAN and B3LYP. Together, these results suggest that SRC1-r1 is only appropriate for use in conjunction with TD-DFT, not with ∆SCF or eigenvalue-based methods.