The MAE for UDFT//AP and AP//AP model chemistries were essentially identical (∆MAE < 0.1 kcal/mol), and the MAE of α > 1 cases of these two methods were 3.04 and 2.98 kcal/mol (See Table ). From our results, solvent effects for this test set do not seem to be significant. Overall, AP provides reasonably good results for spin crossover gaps predicted by UDFT.