On the Multi-Reference Nature of Plutonium Oxides: PuO<sub>2</sub><sup>2+</sup>, PuO<sub>2</sub>, PuO<sub>3</sub> and PuO<sub>2</sub>(OH)<sub>2</sub> - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Chemistry Chemical Physics Année : 2017

On the Multi-Reference Nature of Plutonium Oxides: PuO22+, PuO2, PuO3 and PuO2(OH)2

Résumé

Actinide-containing complexes present formidable challenges for electronic structure methods due to the large number of degenerate or quasi-degenerate electronic states arising from partially occupied 5f and 6d shells. Conventional multi-reference methods can treat active spaces that are often at the upper limit of what is required for a proper treatment of species with complex electronic structures, leaving no room for verifying their suitability. In this work we address the issue of properly defining the active spaces in such calculations, and introduce a protocol to determine optimal active spaces based on the use of the Density Matrix Renormalization Group algorithm and concepts of quantum information theory. We apply the protocol to elucidate the electronic structure and bonding mechanism of volatile plutonium oxides (PuO2 and PuO2(OH)2), species associated with nuclear safety issues for which little is known about the electronic structure and energetics. We show how, within a scalar relativistic framework, orbital-pair correlations can be used to guide the definition of optimal active spaces which provide an accurate description of static/non-dynamic electron correlation, as well as to analyse the chemical bonding beyond a simple orbital model. From this bonding analysis we are able to show that the addition of oxo- or hydroxo-groups to the plutonium dioxide species considerably changes the pi-bonding mechanism with respect to the bare triatomics, resulting in bent structures with a considerable multi-reference character.

Dates et versions

hal-01435717 , version 1 (15-01-2017)

Identifiants

Citer

Katharina Boguslawski, Florent Réal, Paweł Tecmer, Corinne Dupperouzel, André Severo Pereira Gomes, et al.. On the Multi-Reference Nature of Plutonium Oxides: PuO22+, PuO2, PuO3 and PuO2(OH)2. Physical Chemistry Chemical Physics, 2017, 19, pp.4317-4329. ⟨10.1039/C6CP05429C⟩. ⟨hal-01435717⟩
156 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More