Study on the electronic structures and absorption spectra for sheelite- and the sheelite-like structures lead tungstate crystal

The electronic structures and absorption spectra of perfect crystals and crystals containing lead vacancy V pb 2 - for both sheelite(PbWO4) and sheelite-like(Pb7.5W8O32) structures have been calculated using density functional theory with the lattice structure optimized. The optical properties of lead tungstate exhibit anisotropy. Numerical calculation shows that the absorption spectra of the sheelite structure crystal containing V pb 2 - exhibit additional absorption bands in the visible and near ultra-violet ranges. However, this is not the case for other structures of the PWO crystals such as the sheelite structure crystal without lead vacancy and the sheelite-like structure crystal with or without lead vacancy.