Obtaining　reasonable　geometric　and　electronic　structures　of　excited　states　is　essential　for　accurately　predicting　the　thermally　activated　delayed　fluorescence　(TADF)　for　the　application　in　organic　light-emitting　diodes　(OLEDs).　Both　electronic　and　geometric　factors　are　evaluated　using　density　functionals　for　reproducing　the　vertical　emission　(EVE(S1))　and　singlet-triplet　splitting　energies　(ΔEST)　of　28　typical　TADF　molecules.　It　is　found　that　most　TADF　molecules　(charge-transfer　type)　can　easily　twist　upon　excitation,　indicating　the　importance　of　constructing　a　rigid　molecular　structure　for　improving　the　performance　of　TADF　OLEDs.　Functionals　with　insufficient　exact　exchange　will　result　in　the　substantial　underestimation　of　the　relaxation　energy　of　T1,　suggesting　that　the　hybrid　functionals　such　as　B3LYP　should　not　be　used.　Overall,　the　best　approach　for　calculating　EVE(S1)　and　EST　is　the　descriptor-tuned　LC-ωPBELOL　functional　combining　the　CAM-B3LYP-optimized　excited-state　geometries,　which　shows　mean　absolute　deviations　of　0.21　and　0.10　eV,　respectively.　©　2019　American　Chemical　Society.