A study on native defects and magnetic properties in undoped rutile TiO2 using LDA and LDA+UO p+UTi d methods

The native defects and magnetic properties in undoped rutile TiO 2 are studied using local density approximation (LDA) and LDA adding Hubbard parameters ( U ) schemes. The band gap is adjusted to experimental value of 3.0 eV by combination of U Ti d =4.2 eV and U O p =4.8 eV. This LDA+ U methodology overcomes the band-gap problem and renders the approach more predictive. The formation energies of oxygen vacancy ( V O ), oxygen interstitial ( O i ), titanium vacancy ( V Ti ), titanium interstitial (Ti i ), oxygen anti-sites (O Ti ), and titanium anti-sites (Ti O ) are investigated by the LDA and LDA+ U methods. In addition, some ground state configurations can be obtained by optimization of total spin. It is found that native defects can induce spin polarization and produce magnetic moment.