Cs2UPd3Se6

Abstract

Dicaesium uranium(IV) tripalladium(II) hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2), Cs1 (222), Cs2 (m2m), Pd1 (.m.), Pd2 (2mm), Se1 (m..), and Se2 (1). This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010). The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.