Band structure and linear optical properties ofKTiOPO4

The electronic structure and optical properties of ${\mathrm{KTiOPO}}_4$ have been calculated using a first-principles self-consistent method. It is shown that the electronic structure is characterized by localized molecular units of ${\mathrm{TiO}}_6$ and ${\mathrm{PO}}_4$. Effective-charge calculation shows K and Ti to be highly ionized while P is also positively ionized because of the charge transfer to O atoms. The presence of the short Ti-O bonds in ${\mathrm{KTiOPO}}_4$ has a profound effect on its electronic structure. The calculated optical properties and their anisotropy are in good agreement with recent experimental measurement.