Electronic π-to-π* Excitations of Rhodamine Dyes Exhibit a Time-Dependent Kohn-Sham Theory "Cyanine Problem".

ABSTRACT: The longest-wavelength π-to-π* electronic excitations of rhodamine-like dyes (RDs) with different group 16 heteroatoms (O, S, Se, Te) have been investigated. Time-dependent Kohn-Sham theory (TDKST) calculations were compared with coupled-cluster (CC) and equations-of-motion (EOM) CC results for π-to-π* singlet and triplet excitations. The RDs exhibit characteristics in the TDKST calculations that are very similar to previously investigated cyanine dyes, in the sense that the singlet energies obtained with nonhybrid functionals are too high compared with the CC results at the SD(T) level. The errors became increasingly larger for functionals with increasing amounts of exact exchange. TDKST with all tested functionals led to severe underestimations of the corresponding triplet excitations an

SUBMITTER: Moore B 

PROVIDER: S-EPMC5474673 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature