title: Localized operator partitioning method for electronic excitation energies in the time-dependent density functional formalism.
abstract: We extend the localized operator partitioning method (LOPM) [J. Nagesh, A. F. Izmaylov, and P. Brumer, J. Chem. Phys. 142, 084114 (2015)] to the time-dependent density functional theory framework to partition molecular electronic energies of excited states in a rigorous manner. A molecular fragment is defined as a collection of atoms using Becke's atomic partitioning. A numerically efficient scheme for evaluating the fragment excitation energy is derived employing a resolution of the identity to preserve standard one- and two-electron integrals in the final expressions. The utility of this partitioning approach is demonstrated by examining several excited states of two bichromophoric compounds: 9-((1- naphthyl)- methyl)- anthracene and 4-((2- naphthyl)- methyl)- benzaldehyde. The LOPM is found to provide nontrivial insights into the nature of electronic energy localization that is not accessible using a simple density difference analysis.
authors.affiliation: Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Jayashree
authors.initials: J
authors.lastname: Nagesh
authors.affiliation: Gaussian, Inc., 340 Quinnipiac Street, Building 40, Wallingford, Connecticut 06492, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Frisch
authors.affiliation: Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Brumer
authors.affiliation: Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Artur F
authors.initials: AF
authors.lastname: Izmaylov