Atomic structure of a Ultrathin TiO$_{2}$ film on Mo(112) surface*

Materials with reduced dimensions attract much interest because their properties are often significantly different from the properties of bulk materials. Additionally, thin oxide films represent model systems well suited for studying structure reactivity relationships on oxides and oxide supported metal particles considered as models for heterogeneous catalysts. Recently, gold clusters on titania/Mo(112) surface are found to be high catalytic activity, attributing to the structural effects. Despite extensive experimental and theoretical studies the detailed atomic structure of TiO$_{2}$ films on Mo(112) substrate remain unknown. The geometrical and electronic structures of a ultrathin TiO$_{2}$ film expitaxially grown on a Mo(112) substrate have been determined by first principles density-functional theory calculations. The results show that the TiO$_{2}$ perfer to the 8$\times $2 surface structure on the Mo(112) surface, which is well agreement with the experiments.