Crystal structure of the mixed-metal thio-phosphate Nb1.18V0.82PS10.

The mixed-metal thio-phosphate, Nb1.18V0.82PS10 (niobium vanadium phospho-rus deca-sulfide), has been prepared though solid state reactions using an alkali-metal halide flux. The title compound is isostructural with two-dimensional Nb2PS10. [M 2S12] (M = Nb or V) dimers built up from two bicapped trigonal prisms and tetra-hedral [PS4] units share sulfur atoms to construct (1) ∞[M 2PS10] chains along the a axis. These chains are linked through the di-sulfide bonds between [PS4] units in adjacent chains to form layers parallel to the ab plane. These layers then stack on top of each other to complete the three-dimensional structure with van der Waals gaps. The M sites are occupied by 59% of Nb and 41% of V and the average M-S and M-M distances in the title compound are in between those of V2PS10 and Nb2PS10. The classical charge balance of the title compound can be represented by [(Nb/V)(4+)]2[P(5+)][S(2-)]3[S(-)]7.