The electronic structures of the perfect BaMoO4 and BaMoO4 crystals containing an interstitial oxygen atom situated at an appropriate position with the total energy being the lowest were studied within the framework of the density functional theory with the lattice structure optimized. The calculated results revealed that the interstitial oxygen atom situated at two different interstitial sites would combine with formal lattice oxygen ions forming molecular ions in two different ways, and the interstitial oxygen atom would cause visible range absorption band peaked at about 320nm.

Ab initio Study of Electronic Structures of BaMoO4 Crystals Containing an Interstitial Oxygen Atom. H.Zhao, F.Zhang, X.Guo, Q.Zhang, T.Liu: Journal of Physics and Chemistry of Solids, 2010, 71[12], 1639-43