The quinter­nary thio­phosphate Cs(0.5)Ag(0.5)Nb(2)PS(10)

The quinter­nary thio­phosphate Cs(0.5)Ag(0.5)Nb(2)PS(10), cesium silver tris­(disulfido)[tetra­thio­phosphato(V)]diniobate(IV), has been prepared from the elements using a CsCl flux. The crystal structure is made up of (∞) (1)[Nb(2)PS(10)] chains expanding along [010]. These chains are built up from bicapped trigonal-prismatic [Nb(2)S(12)] units and tetra­hedral [PS(4)] groups and are linked through a linear S—Ag—S bridge, forming a two-dimensional layer. These layers then stack on top of each other, completing the three-dimensional structure with an undulating van der Waals gap. The disordered Cs(+) ions reside on sites with half-occupation in the voids of this arrangement. Short [2.8843 (5) Å] and long [3.7316 (4) Å] Nb—Nb distances alternate along the chains, and anionic S(2) (2−) and S(2−) species are observed. The charge balance of the com­pound can be represented by the formula [Cs(+)](0.5)[Ag(+)](0.5)[Nb(4+)](2)[PS(4) (3−)][S(2) (2−)](3).