Other functionals such as ωB97X-V, LRC-ωPBE, and LRC-ωPBEh also afford larger ∆SCF errors as compared to SCAN, with MAEs of 0.5 eV for ωB97X-V and LRC-ωPBEh, and 0.8 eV for LRC-ωPBE. Regarding the LRC functionals, it is interesting to note how the error is reduced by the addition of short-range HFX, yet neither functional is as accurate as HF theory itself. There is some precedent for this observation in a recent ∆SCF study of K-, L-, and M-shell ionization energies of Ni and Cu atoms, where it was found that HF calculations were more accurate than a broad array of density functionals, although SCAN was not tested in that work. In Ref. 39, the hybrid functional PBEh(α) was applied to the CORE65 data set, optimizing the fraction of HFX to minimize the errors. The optimal fraction was found to be α = 0.45, affording a MAE of 0.33 eV that is only slightly better than HF theory (MAE = 0.41 eV).