A generalized Brillouin theorem (GBT)-like implementation to optimize Valence Bond wave function for excited states

Julien Racine (1) , Yannick Carissan (2, 1) , Denis Hagebaum-Reignier (2, 1) , Stéphane Humbel (1)

1 ISM2 - Institut des Sciences Moléculaires de Marseille
2 CTOM - Chimie Theorique et Modèles

A python code coupled to the ab initio Valence Bond code XMVB, is designed to optimize non-orthogonal orbitals in Valence Bond (VB) wave functions that describe excited states. This code can handle both ground and excited states. Our implementation relies on the general Brillouin theorem (GBT) and super configuration interaction (SCI) processes. We tested our program on the ground and the singlet excited V states of the ethene molecule. Both energetic and wave function are used to compare our results with the literature.

Mots clés: valence bond; excited states; electronic structure; super-CI; general Brillouin theorem

Domaines: Chimie théorique et/ou physique

Julien Racine, Yannick Carissan, Denis Hagebaum-Reignier, Stéphane Humbel. A generalized Brillouin theorem (GBT)-like implementation to optimize Valence Bond wave function for excited states. Computational and Theoretical Chemistry, 2017, 1116, pp.184 - 189. ⟨10.1016/j.comptc.2017.01.019⟩. ⟨hal-01469404⟩