Electronic Properties of Uranium Oxide: A Standard DFT and DFT+U Investigation

This paper uses the first principle approach to investigate the electronic properties of uranium oxide. First, the structure was optimized, and the converged parameters were used for the rest of the calculations. For this article, the density functional theory as implemented on the quantum espresso code was, the ultrasoft Perdew Burke Erzhenhorf (PBE) pseudo potential was used, and the 4.0 eV Hubbard parameter was applied to the 5f orbital of the uranium atom in the bulk uranium oxide. The results show that the Hubbard correction applied to the 5f orbital of uranium accounting for the effect of strong electron-electron correlation has improved the electronic properties of uranium oxide by shifting the 5f of uranium orbital away from the Fermi level and increasing the probability of electronic transition from the valence to the conduction band. Finally, the result suggested that Hubbard corrected uranium oxide, which is the best system to use for future calculations, particularly in applications relating to nuclear fuel.