Basis set and functional effects on excited-state properties: Three bicyclic chromogens as working examples

摘要

We have computed, at the time-department density functional theory, TD-DFT level of approximation, the ground- and excited-state properties of three typical chromophores, namely indole, coumarin, and benzofurazan, using six functionals (B3LYP, B3P86, PBE0, BMK, BH&HLYP, and CAM-B3LYP) and four atomic basis sets (BSs), the larger being 6-311++G(2d,2p). It turned out that diffuse functions are necessary to obtain correct vertical transition energies. The selected functional mainly impacts on these energies, but the differences of vibrational energies between the ground- and excited-states are almost BS and functional independent. The adiabatic gap estimated with total energies or with Gibbs free enthalpies are nearly the same provided the ZPVE effects are accounted for.