Lithium barium silicate,Li2BaSiO4, from synchrotron powder data

The structure of lithium barium silicate, Li₂BaSiO₄, has been determined from synchrotron radiation powder data. The title compound was synthesized by high‐temperature solid‐state reaction and crystallizes in the hexagonal space group P6₃cm. It contains two Li atoms, one Ba atom (both site symmetry ..m on special position 6c), two Si atoms on special positions 4b (site symmetry 3..) and 2a (site symmetry 3.m)] and four O atoms (one on general position 12d, and three on special positions 6c, 4b and 2a). The basic units of the structure are (Li₆SiO₁₃)^5? units, each comprising seven tetrahedra sharing edges and vertices. These basic units are connected by sharing corners parallel to 001] and through sharing (SiO₄)^4? tetrahedra in (001). The relationship between the structures and luminescence properties of Li₂SrSiO₄, Li₂CaSiO₄ and the title compound is discussed.