Calculated Electronic Properties of Rutile TiO$_{2}$ and Cubic SrTiO$_{3 }$

We present preliminary, calculated, electronic properties of rutile titanium dioxide (TiO$_{2})$ and of cubic strontium titanate (SrTiO$_{3})$. Our computations employed local density approximation (LDA) and generalized gradient Approximation (GGA) potentials for TiO$_{2}$ and SrTiO$_{3}$, respectively. We implemented the linear combination of atomic orbitals (LCAO) within the framework of the Bagayoko, Zhao, and Williams (BZW) method. In doing so, we solved, self-consistently, both the Kohn-Sham equation and the equation giving the ground state charge density in terms of the wave functions of the occupied states. Our preliminary findings indicate that TiO$_{2}$ has an indirect band gap of 2.95 eV, from $\Gamma $ to R. The direct gap at $\Gamma $ is 0.10 eV larger. The indirect band gap of SrTiO$_{3}$, from L to $\Gamma $ or X, is 3.05 eV. \\[4pt] Work funded in part by the Louisiana Optical Network Initiative (LONI), the National Science Foundation (NSF) and the Louisiana Board of Regents [Award Nos. EPS-1003897 and NSF (2010-15)-RII-SUBR], and and Ebonyi State, Federal Republic of Nigeria [Award No: EBSG/SSB/FSA/040/VOL. VIII/039]