Excited-State Dipole and Quadrupole Moments: TD-DFT versus CC2.

ABSTRACT: The accuracies of the excited-state dipole and quadrupole moments obtained by TD-DFT are assessed by considering 16 different exchange-correlation functionals and more than 30 medium and large molecules. Except for excited-state presenting a significant charge-transfer character, a relatively limited dependency on the nature of the functional is found. It also turns out that while DFT ground-state dipole moments tend to be too large, the reverse trend is obtained for their excited-state counterparts, at least when hybrid functionals are used. Consequently, the TD-DFT excess dipole moments are often too small, an error that can be fortuitously corrected for charge-transfer transition by selecting a pure or a hybrid functional containing a small share of exact exchange. This error-cancelatio

SUBMITTER: Jacquemin D 

PROVIDER: S-EPMC4980690 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature