Materials Data on Nb2FeS4 by Materials Project

Abstract

FeNb2S4 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of two FeNb2S4 sheets oriented in the (0, 0, 1) direction. there are two inequivalent Nb+2.50+ sites. In the first Nb+2.50+ site, Nb+2.50+ is bonded to six S2- atoms to form distorted NbS6 octahedra that share corners with two equivalent NbS6 octahedra, corners with two equivalent FeS5 trigonal bipyramids, edges with seven NbS6 octahedra, and edges with three equivalent FeS5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 12°. There are a spread of Nb–S bond distances ranging from 2.48–2.71 Å. In the second Nb+2.50+ site, Nb+2.50+ is bonded to six S2- atoms to form distorted NbS6 octahedra that share corners with two equivalent NbS6 octahedra, a cornercorner with one FeS5 trigonal bipyramid, edges with seven NbS6 octahedra, and edges with two equivalent FeS5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 12°. There are a spread of Nb–S bond distances ranging from 2.36–2.87 Å. Fe3+ is bonded to five S2- atoms to form distorted FeS5 trigonal bipyramids that share corners with three NbS6 octahedra, edges with five NbS6 octahedra, and edges with two equivalent FeS5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 16–19°. There are a spread of Fe–S bond distances ranging from 2.28–2.77 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three Nb+2.50+ atoms. In the second S2- site, S2- is bonded in a distorted T-shaped geometry to one Nb+2.50+ and two equivalent Fe3+ atoms. In the third S2- site, S2- is bonded in a 5-coordinate geometry to three equivalent Nb+2.50+ and two equivalent Fe3+ atoms. In the fourth S2- site, S2- is bonded to five Nb+2.50+ and one Fe3+ atom to form distorted edge-sharing SNb5Fe octahedra.