Intrinsic band gap in semiconductor oxides and Ti-silicalite: Ab initio and DFT study

Here we present the results of ab initio and DFT calculations mimicking the effect of transition metal ions on electronic and structural properties of Ti-silicalite, as well as of Na and N on rutile structures. The main discussion focuses on the excitation shifts into the longer wavelength region and their relation to the frontier orbitals that are expected to be responsible for the observed band gap changes. The results obtained allow us to give some insight in understanding the target phenomenon, as well as to point out on the importance of boundary frontier orbitals. These and other related findings are presented.