Data Overview. In the QUESTDB database, excitations from many methods are only reported for the 491 excitations from closed-shell (S 0 ) molecules, and, due to double excitations and strongly mixed states, results from most methods are only available for about 460 of these excitations (SI Figure ). Our Aug (12,12) results comprise of 436 excitations included by T SA-CASSCF = 1.1 eV, 399 of which come from closed-shell molecules. Combining all methods and leaving out STEOM-CCSD, CCSDR(3), and CCSDT-3 for which there is significantly less available data (SI Figure ), there are a total of 373 excitations consis-tently available for comparison with SA-CASSCF, tPBE0, NEVPT2, and 12 other methods in the QUESTDB database. Unlike Jacquemin and coworkers, we have not limited ourselves to comparisons based on "safe" 65,66 excitations, and this includes 29 excitations that would otherwise have been excluded (out of a total of 57 unsafe excitations in the total set of 542). Figure shows the mean absolute and signed errors of SA-CASSCF, tPBE, tPBE0, and NEVPT2 in comparison with 12 other methods in the QUESTDB database on the set of 373 excitations. First considering the mean absolute errors, we find that both NEVPT2 (0.18 eV) and tPBE0 (0.19 eV) have accuracy on par with CC2 (0.15 eV), with tPBE lagging significantly behind (0.24 eV). However, we note that the errors we report here for tPBE, tPBE0, and NEVPT2 are likely slightly overestimated, as our CASSCF error threshold is imperfect and fails to eliminate all cases with poor active space choices (as discussed in the Supporting Information).