Acta Cryst. (2009). E65, i56-i57  [ doi:10.1107/S1600536809025100 ]

Redetermination of AgNb₂PS₁₀ revealing a silver deficiency

J. Do and H. Yun

Abstract: In comparison with a previous crystallographic study [Goh et al. (2002). J. Solid State Chem. 168, 119-125] of the title compound, silver diniobium tris(disulfide) tetrathiophosphate(V), that reports a full occupation of the silver position and isotropic displacement parameters for the atoms, the current redetermination reveals a silver deficiency with a site-occupation factor of 0.88 (1) and reports all atoms with anisotropic displacement parameters. The structure of Ag_0.88Nb₂PS₁₀ is composed of ¹[Nb₂PS₁₀] chains, which are built up from pairs of distorted bicapped trigonal-prismatic [NbS₈] polyhedra forming [Nb₂S₁₂] dimers and of tetrahedral [PS₄] groups. These chains are connected via the statistically disordered Ag⁺ ions, forming double layers. Adjacent layers are stacked solely through van der Waals forces into a three-dimensional structure. Short and long Nb-Nb distances [2.880 (1) and 3.770 (2) Å, respectively] alternate along the chain and S₂^2- and S^2- anionic species are observed.

Online 4 July 2009

Copyright © International Union of Crystallography
IUCr Webmaster