First‐principles study of the electronic structures and absorption spectra for the PbMoO 4 crystal with lead vacancy

The electronic structures and absorption spectra for the perfect PbMoO 4 crystal and the crystal containing lead vacancy $ {\rm V}^{2-}_{\rm Pb} $ with lattice structure optimized are calculated using density functional theory code CASTEP. The calculated absorption spectra of the PbMoO 4 crystal containing $ {\rm V}^{2-}_{\rm Pb} $ exhibit three absorption bands peaking at 2.0 eV (620 nm), 3.0 eV (413 nm) and 3.3 eV (375 nm), which are in good agreement with experimental values. The theory predicts that the 390 nm, 430 nm and 580 nm absorption bands are related to the existence of $ {\rm V}^{2-}_{\rm Pb} $ in the PbMoO 4 crystal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)