Effect of Mott-Hubbard correlations on the electronic structure and structural stability of uranium dioxide

• Published in: Philosophical magazine. B, Physics of condensed matter. Structural, electronic, optical, and magnetic properties. Vol. 75; no. 5; pp. 613 - 628
• Main Authors: Dudarev, S. L., Manh, D. Nguyen, Sutton, A. P.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.05.1997
• ISSN: 1364-2812; 1463-6417
• DOI: 10.1080/13642819708202343

The influence of Mott-Hubbard electron-electron correlations on the electronic structure and structural stability of uranium dioxide (UO 2 ) has been analysed using the local spin-density approximation (LSDA) + U approach. We have found that the inclusion of a term describing the Hubbard on-site repulsion between 5f electrons results in a dramatic improvement in the description of the equilibrium electronic and magnetic structure of UO 2 for which conventional LSDA calculations incorrectly predict a non-magnetic metallic ground state. We have found that the presence of electron-electron correlations in the 5f band modifies the character of chemical bonding in the material, leading to a Heitler-London type of hybridization between the 5f orbitals and giving rise to a larger value of the equilibrium lattice constant in better agreement with experimental observations.