title: A Simple One-Body Approach to the Calculation of the First Electronic Absorption Band of Water.
abstract: A one-body decomposition approach for investigating the electronic absorption spectra of molecular systems was proposed and applied to water clusters (H2O)N including up to N = 80 water molecules. Two specific aspects of the present implementation are the inclusion of the coupling between excited states and a simplified representation for the N-body Coulombic effects. For smaller clusters, the results based on the one-body decomposition scheme are in good agreement with full EOM-CCSD calculations. Two different regimes can be identified in the electronic absorption profile of larger water clusters. The first low-energy regime is dominated by local excitonic states on the cluster surface, whereas the higher-energy excitations associated with the second one are of delocalized nature.
authors.affiliation: Grupo de Física-Matemática da Universidade de Lisboa, Avenue Professor Gama Pinto 2, 1649-003 Lisboa, Portugal, Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Mata
authors.affiliation: Grupo de Física-Matemática da Universidade de Lisboa, Avenue Professor Gama Pinto 2, 1649-003 Lisboa, Portugal, Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
authors.forename: Hermann
authors.initials: H
authors.lastname: Stoll
authors.affiliation: Grupo de Física-Matemática da Universidade de Lisboa, Avenue Professor Gama Pinto 2, 1649-003 Lisboa, Portugal, Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
authors.forename: B J Costa
authors.initials: BJ
authors.lastname: Cabral