inorganic compounds
The structure of tetragermanium strontium nonaoxide, SrGe4O9, comprises two different types of sheet structure stacked alternately along the c axis. One sheet comprises the GeO6 octahedra and the SrO8 polyhedra while the other sheet contains three-membered rings of GeO4 tetrahedra. In addition, this crystal structure shows a basic unit of the super structures which are found in PbGe4O9.