We next consider the SIE4x4 data set, which consists of dissociation energies for H + 2 , He + 2 , (NH 3 ) + 2 , and (H 2 O) + 2 at intermolecular distances R = R e (equilibrium separation) and also R = 1.25R e , 1.50R e , and 1.75R e . These are challenging systems for many functionals, due to SIE problems. The data for SIE4x4 in Fig. reflect the an- ticipated trend, with errors decreasing as the fraction of exact exchange increases, starting from BLYP+D3 that exhibits the largest errors. The BH&H-LYP functional (α = 50) outperforms ωB97M-V for SIE4x4, as does B(60)LYP+D3, while B(40)LYP+D3 is on par with ωB97M-V. For these SIE-dominated problems, there is clear merit in enhancing the fraction of exact exchange and it is precisely for these type of CT complexes where BH&H-LYP has often been deployed in the past. The final data set that we examine in detail is DC13, consisting of 13 large system reaction energies and isomerization energies that are considered to be challenging for DFT. MAEs for all of the B(α)LYP+D3 functionals lie within about 4 kcal/mol of one another. Each is superior to BLYP+D3 and comparable to B3LYP+D3, except (arguably) for the α = 20 functional whose error is a bit larger. Of the B(α)LYP+D3 functionals, however, BH&H-LYP+D3 is the best, outperforming even B3LYP+D3 and suggesting that 50% exact exchange is beneficial for these challenging cases.