Hybrid functional study on structural and electronic properties of oxides

The hybrid functional method within the HSE06 scheme is tested on various oxides such as TiO2, SrTiO3, ZnO, SnO2, MgO, SiO2, and Al2O3. Since the canonical mixing parameter still underestimates the energy gap, we optimize it by fitting the energy gap to the experimental value. It is found that optimized values lie between 0.2 and 0.4 depending on the material. The structural properties are examined and the lattice parameters calculated with the HSE06 functional are in better agreement with experiment compared to (semi)local functional results. The relative shifts in the valence and conduction edges are provided, which can serve as first-order corrections to the semilocal functional results on defect levels or interfacial band offsets.