Computational prediction for singlet- and triplet-transition energies of charge-transfer compounds

Our work reveals a high dependence on charge-transfer (CT) amounts for the optimal Hartree-Fock percentage in the exchange-correlation functional of time-dependent density functional theory (TD-DFT) and the error of a vertical transition energy calculated by a given functional. Using these relations, the zero-zero transition energies of the first singlet and first triplet excited states of various CT compounds are accurately reproduced. ³CT and locally excited triplet (³LE) states are well distinguished and calculated independently.