Sr(9)La(2)(WO(6))(4) containing [WO(6)] octa­hedra

A polycrystalline sample of Sr(9)La(2)(WO(6))(4), nona­strontium dilanthanum tetra­kis­[orthotungstate(VI)], was prepared by heating a compacted powder mixture of SrCO(3), WO(3), and La(2)O(3) with an Sr:La:W molar ratio of 9:2:4 at 1473 K. X-ray crystal structure analysis was performed for a Sr(9)La(2)(WO(6))(4) single-crystal grain grown by reheating the sample at 1673 K. Sr(9)La(2)(WO(6))(4) crystallizes with four formula units in the tetra­gonal space group I4(1)/a and is isotypic with Sr(11)(ReO(6))(4). Two W sites with site symmetries of [Image: see text] are located at the center of isolated [WO(6)] octa­hedra, and four mixed (Sr/La) sites are surrounded by eight to twelve O atoms of the [WO(6)] octa­hedra. The structure of Sr(9)La(2)(WO(6))(4) can be described on the basis of the double-perovskite structure with [WO(6)] and [(Sr/La)O( x )] polyhedra alternately placed, and a vacancy (□).