Thallium(I) copper(I) thorium(IV) tris­elenide, TlCuThSe₃

Thallium(I) copper(I) thorium(IV) tris­elenide, TlCuThSe₃, crystallizes with four formula units in the space group Cmcm in the KCuZrS₃ structure type. There is one crystallographic­ally independent Th, Tl, and Cu atom at a site of symmetry 2/m.., m2m, and m2m, respectively. There are two crystallographically independent Se atoms at sites of symmetry m.. and m2m. The structure consists of sheets of edge-sharing ThSe₆ octa­hedra and CuSe₄ tetra­hedra stacked parallel to the (010) face, separated by layers filled with chains of Tl running parallel to [100]. Each Tl is coordinated by a trigonal prism of Se atoms.