  Physically reasonable electronic structures of reconstructed rutile
TiO_2(110)-(1x2) surfaces were studied using density functional theory (DFT)
supplemented with Hubbard U on-site Coulomb repulsion acting on the d
electrons, so called as the DFT+U approach. Two leading reconstruction models
proposed by Onishi--Iwasawa and Park et al. were compared in terms of their
thermodynamic stabilities.
