This reduction in binding can be beneficial if the unscaled functional (significantly) overbinds the benzene excimer, such that the spin-scaled variants end up closer to the reference than the unscaled functional. This is the case for ωPBEPP86 [Fig ] where an overestimation in D e of 7.87 kcal/mol (58% error, largest for benzene excimer) is reduced to 3.55 and 1.31 kcal/mol for SCS-and SOS-ωPBEPP86. Similarly, the deviation for ωB88PP86 is favourably reduced, for example SCS-ωB88PP86 deviates by only 0.23 kcal/mol from the reference D e . However, if the unscaled functional already underbinds the benzene excimer, scaled variants increase the deviation from the reference, which in the case of SOS-B2GP-PLYP [Figure ] results in the largest underbinding of the benzene excimer, by 5.98 kcal/mol (44% error).