First-principles LDA+U and GGA+U study of plutonium oxides

TL;DR

This study uses first-principles calculations with LDA+U and GGA+U methods to analyze the electronic structure and properties of plutonium oxides PuO₂ and Pu₂O₃, focusing on how computational parameters influence results.

Contribution

It demonstrates that appropriate U values in LDA+U and GGA+U methods enable accurate modeling of plutonium oxides' properties and redox reactions.

Findings

Proper U selection yields accurate structural and electronic properties.

Oxidation of Pu₂O₃ to PuO₂ depends on U and exchange-correlation choice.

First-principles approach can model redox processes in Pu materials.

Abstract

The electronic structure and properties of PuO$_{2}$ and Pu$_{2}$O$_{3}$ have been studied from first principles by the all-electron projector-augmented-wave (PAW) method. The local density approximation (LDA)+$U$ and the generalized gradient approximation (GGA)+$U$ formalism have been used to account for the strong on-site Coulomb repulsion among the localized Pu $5f$ electrons. We discuss how the properties of PuO$_{2}$ and Pu$_{2}$O$_{3}$ are affected by the choice of $U$ as well as the choice of exchange-correlation potential. Also, oxidation reaction of Pu$_{2}$O$_{3}$, leading to formation of PuO$_{2}$, and its dependence on $U$ and exchange-correlation potential have been studied. Our results show that by choosing an appropriate $U$ it is promising to correctly and consistently describe structural, electronic, and thermodynamic properties of PuO$_{2}$ and Pu$_{2}$O$_{3}$, which enables it possible the modeling of redox process involving Pu-based materials.