Electronic structure of UO2 from the density functional theory with on-site Coulomb repulsion

We have investigated the electronic structure and the bonding characteristics Of UO2 by using density functional theory calculations. With the Coulomb correlation U included, an insulating ground state with the antiferromagnetism is correctly predicted. The energy-band structure, projected density of states, and partial charge analysis show that the band-gap opening and the magnetism are governed by the partially filled U 5f bands. We also find that four out of the seven 5f subshells hybridize with the neighboring O 2p(x,y) orbitals and are responsible for the chemical bonding in UO2.