Correlation effects and energetics of point defects in uranium dioxide: a first principle investigation

Density functional (DFT) calculations have been used to investigate the stability of point defects in uranium dioxide. Correlation effects are taken into account within the DFT + U approach as implemented in the Vienna ab initio simulation package (VASP). More particularly, the formation energies of both intrinsic and extrinsic point defects, i.e. vacancies, interstitials, Frenkel pairs and Schottky trio defects, are calculated. Our results are compared with available experimental data and are also discussed in relation to previous calculations based on conventional functionals, such as the local spin-density approximation and generalized gradient approximations.