title: Revisiting the relationship between the bond length alternation and the first hyperpolarizability with range-separated hybrid functionals.
abstract: We monitor the influence of the bond length alternation (BLA) modification on the static electronic polarizability and first hyperpolarizability of two polymethineimine oligomers. Four theoretical approaches are compared: HF, PBE0, LC-omegaPBE, and MP2. For the dodecamer, both HF and PBE0 are unable to foresee even the qualitative evolution of the first hyperpolarizability when varying the BLA. On the contrary, LC-omegaPBE provides (non)linear optics properties in agreement with MP2 results, especially for the longer chains. This confirms the interest of range-separated hybrids for the computation of the (hyper)polarizabilities of extended pi-conjugated compounds.
authors.affiliation: Laboratoire de Chimie Théorique Appliquée, Groupe de Chimie Physique Théorique et Structurale, Facultés Universitaires Notre-Dame de la Paix, rue de Bruxelles, 61, B-5000 Namur, Belgium. denis.jacquemin@fundp.ac.be
authors.forename: Denis
authors.initials: D
authors.lastname: Jacquemin
authors.forename: Eric A
authors.initials: EA
authors.lastname: Perpéte
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ciofini
authors.forename: Carlo
authors.initials: C
authors.lastname: Adamo