Boron-doped anatase: electronic band structure, boron atom locations and magnetic state

The first-principle spin-resolved GGA and GGA+U calculations for the electronic band structure of the boron-doped TiO$_{2}$ with anatase structure have been performed. The locations of boron atoms in the interstitial and oxygen position have been studied. We have found two interstitial positions: a stable one with three neighboring oxygen atoms, and a metastable one in the center of the flattened tetrahedron of oxygen atoms. The boron location in interstitial position is energetically more favorable than the location inside the oxygen position. In accordance with experiments, the GGA+U approach produces spin-polarized solutions for interstitial boron positions, whereas the GGA approach fails to produce a spin-polarized solution.