title: Properties of atoms in electronically excited molecules within the formalism of TDDFT.
abstract: The topological analysis of the electron density for electronic excited states under the formalism of the quantum theory of atoms in molecules using time-dependent density functional theory (TDDFT) is presented. Relaxed electron densities for electronic excited states are computed by solving a Z-vector equation which is obtained by means of the Sternheimer interchange method. This is in contrast to previous work in which the electron density for excited states is obtained using DFT instead of TDDFT, that is, through the imposition of molecular occupancies in accordance with the electron configuration of the excited state under consideration. Once the electron density of the excited state is computed, its topological characterization and the properties of the atoms in molecules are obtained in the same manner that for the ground state. The analysis of the low-lying π→π* singlet and triplet vertical excitations of CO and C6H6 are used as representative examples of the application of this methodology. Altogether, it is shown how this procedure provides insights on the changes of the electron density following photoexcitation and it is our hope that it will be useful in the study of different photophysical and photochemical processes.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D. F. México.
authors.forename: Eric Iván
authors.initials: EI
authors.lastname: Sánchez-Flores
authors.affiliation: Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D. F. México.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Chávez-Calvillo
authors.affiliation: Semichem, Inc., 12456 West 62nd Terrace, Suite D Shawnee, Kansas, 66216.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Keith
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D. F. México.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cuevas
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D. F. México.
authors.forename: Tomás
authors.initials: T
authors.lastname: Rocha-Rinza
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D. F. México.|Departamento de Química Teórica, Centro Conjunto de Investigación en Química Sustentable UAEMex-UNAM, Carretera Toluca-Atlacomulco km 14.5, C.P. 50200, Toluca, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Cortés-Guzmán
keywords: TDDFT; aromaticity; delocalization indexes; excited states; properties of atoms in molecules