Penta-europium dicadmium penta-anti-monide oxide, Eu(5)Cd(2)Sb(5)O.

The title compound, Eu(5)Cd(2)Sb(5)O adopts the Ba(5)Cd(2)Sb(5)F-type structure (Pearson symbol oC52), which contains nine crystallographically unique sites in the asymmetric unit, all on special positions. One Eu, two Sb, and the Cd atom have site symmetry m..; two other Eu, the third Sb and the O atom have site symmetry m2m; the remaining Eu atom has 2/m.. symmetry. Eu atoms fill penta-gonal channels built from corner-sharing CdSb(4) tetra-hedra. The isolated O atom, i.e., an oxide ion O(2-), is located in a distorted tetra-hedral cavity formed by four Eu cations.