title: Quantifying local exciton, charge resonance, and multiexciton character in correlated wave functions of multichromophoric systems.
abstract: A new method for quantifying the contributions of local excitation, charge resonance, and multiexciton configurations in correlated wave functions of multichromophoric systems is presented. The approach relies on fragment-localized orbitals and employs spin correlators. Its utility is illustrated by calculations on model clusters of hydrogen, ethylene, and tetracene molecules using adiabatic restricted-active-space configuration interaction wave functions. In addition to the wave function analysis, this approach provides a basis for a simple state-specific energy correction accounting for insufficient description of electron correlation. The decomposition scheme also allows one to compute energies of the diabatic states of the local excitonic, charge-resonance, and multi-excitonic character. The new method provides insight into electronic structure of multichromophoric systems and delivers valuable reference data for validating excitonic models.
authors.affiliation: Kimika Fakultatea, Euskal Herriko Unibersitatea (UPV/EHU) and Donostia International Physics Center (DIPC), P.K. 1072, 20018 Donostia, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Casanova
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
authors.forename: Anna I
authors.initials: AI
authors.lastname: Krylov