Date Published: January 01, 2009
Publisher: International Union of Crystallography
Author(s): Hoseop Yun, Gangbeom Kim.
The new layered ternary sulfide, Nb1.30Cr0.70S5, niobium chromium pentasulfide, is isostructural with the solid solution Nb1+xV1−xS5 and belongs to the FeNb3Se10 structure type. Each layer is composed of two unique chains of face-sharing [NbS8] bicapped trigonal prisms (m symmetry) and edge-sharing [MS6] (M= Nb, Cr) octahedra (m symmetry). One of the two metal sites is occupied by statistically disordered Nb and Cr atoms, with 0.3 and 0.7 occupancy, respectively. The chains are connected along the c axis, forming two-dimensional layers, which then stack on top of each other to complete the three dimensional structure. As a result, an undulating van der Waals gap is found between the layers.
The title compound is isostructural with FeNb3Se10 (Meerschaut et al., 1981 ▶), Cr1.70Nb2.30Se10 (Mori et al., 1984 ▶) and Nb1+xV1−xS5 (Yun et al., 2003 ▶). For the structure of a related niobium sulfide, see: Rijnsdorp & Jellinek (1978 ▶). For ionic radii, see: Shannon (1976 ▶). For related literature and background, see: Kim & Yun (2002 ▶); Gelato & Parthé (1987 ▶).