title: Electron transfer beyond the static picture: a TDDFT∕TD-ZINDO study of a pentacene dimer.
abstract: We use time-dependent density functional theory and time-dependent ZINDO (a semi-empirical method) to study transfer of an extra electron between a pair of pentacene molecules. A measure of the electronic transfer integral is computed in a dynamic picture via the vertical excitation energy from a delocalized anionic ground state. With increasing dimer separation, this dynamical measurement of charge transfer is shown to be significantly larger than the commonly used static approximation (i.e., LUMO+1-LUMO of the neutral dimer, or HOMO-LUMO of the charged dimer), up to an order of magnitude higher at 6 Å. These results offer a word of caution for calculations involving large separations, as in organic photovoltaics, where care must be taken when using a static picture to model charge transfer.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
authors.forename: Randa
authors.initials: R
authors.lastname: Reslan
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lopata
authors.forename: Christopher
authors.initials: C
authors.lastname: Arntsen
authors.forename: Niranjan
authors.initials: N
authors.lastname: Govind
authors.forename: Daniel
authors.initials: D
authors.lastname: Neuhauser