I(8)Sb(10)Ge(36)

Single crystals of the title compound, octa­iodide deca­anti­monate hexa­tria­conta­germanide, were grown by chemical transport reactions. The structure is isotypic with the analogous clathrates-I. In this structure, the (Ge,Sb)(46) framework consists of statistically occupied Ge and Sb sites that atoms form bonds in a distorted tetra­hedral arrangement. They form polyhedra that are covalently bonded to each other by shared faces. There are two polyhedra of different sizes, viz. a (Ge,Sb)(20) dodeca­hedron and a (Ge,Sb)(24) tetra­cosa­hedron in a 1:3 ratio. The guest atom (iodine) resides inside these polyhedra with symmetry m3 (Wyckoff position 2a) and [Image: see text]2m (Wyckoff position 2d), respectively.