On the role of strong electron correlations in the surface properties and chemistry of uranium dioxide
Abstract
We report density functional calculations of the surface properties and chemistry of UO2(111) performed within the generalized gradient approximation corrected with an effective Hubbard parameter (GGA + U within Dudarev's formalism) to account for the strong on-site Coulomb repulsion between U 5f electrons. The variation of the properties of periodic slab models, with collinear ferromagnetic and antiferromagnetic arrangements of the uranium magnetic moments, was investigated while ramping up the effective Hubbard parameter from Ueff = 0 eV, corresponding to standard density functional theory, up to Ueff = 4 eV, the value that correctly reproduces the antiferromagnetic ground state of bulk UO2. The chemical interactions of molecular