title: Methylenecyclopropene: local vision of the first1B2excited state.
abstract: The1A1ground and the first1B2excited states of the methylenecyclopropene (triafulvene) are described by localized wave functions, based on 20 structures valence bond structures. The results are compared to CASSCF(4,4) calculations for both the energetics and the dipole moment. Additional calculations with partial electronic delocalization are presented, and it is shown that the dipole moment modification does not correspond to a situation where the antiaromatic situation prevails (with 4n electrons in the cycle). Part of the analysis uses a "trust factor" that helps to decide if a wave function is appropriate to describe a given state. The trust factor compares the VB wave function to the CASSCF's with their overlap. Finally, the valence bond density is used to produce density maps that illustrate the electron transfer upon excitation. Graphical Abstract A projector-based method compares CASSCF wave functions to local wave functions, including Lewis structures as shown in the picture. A "trust factor" (τ) is obtained. Both the ground state and the first excited state of the methylenecyclopropene are discussed.
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Racine
authors.affiliation: Université Tahar Moulay de Saida, Laboratoire de Modélisation et de Méthodes de Calcul, BP 138 cité ENNASR, 20000, Saida, Algérie.
authors.forename: Mohamed Abdelhak
authors.initials: MA
authors.lastname: Touadjine
authors.affiliation: Université Tahar Moulay de Saida, Laboratoire de Modélisation et de Méthodes de Calcul, BP 138 cité ENNASR, 20000, Saida, Algérie.
authors.forename: Ali
authors.initials: A
authors.lastname: Rahmouni
authors.affiliation: Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France. stephane.humbel@univ-amu.fr.
authors.forename: Stéphane
authors.identifier: http://orcid.org/0000-0001-5405-1848
authors.initials: S
authors.lastname: Humbel
keywords: Dipole moment; Electronic density; Excited state; Valence bond