LDA+U calculated electronic and structural properties of NiO(0 0 1) and NiO(1 1 1) p(2×2) surfaces

In this work, the reconstruction effects for NiO(0 0 1) and oxygen terminated NiO(1 1 1) p(2×2) surfaces have been investigated. The projector augmented wave method together with the Car-Parrinello molecular dynamics scheme have been used to determine the atomic geometry and electronic ground state. The correlation effects of the Ni d electrons are treated using a meanfield multi-orbital Hubbard correction, the so-called LDA+U approximation, to the local spin density Hamiltonian (where LDA stands for the local-density approximation and U for the Hubbard interaction). The LDA+U calculation shows that the reconstruction effects as well as the changes of the electronic structure of the NiO(0 0 1) surface are small compared to the unreconstructed surface. On the contrary, the oxygen-terminated NiO(1 1 1) p(2×2) polar surface exhibits important reconstruction effects and changes of the electronic structure, that provide additional stabilization of this polar surface.