Materials Data on Fe3(WN2)4 by Materials Project
Fe3(WN2)4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent W4+ sites. In the first W4+ site, W4+ is bonded to six N3- atoms to form distorted WN6 pentagonal pyramids that share corners with eight FeN6 octahedra, edges with six WN6 pentagonal pyramids, and faces with two FeN6 octahedra. The corner-sharing octahedra tilt angles range from 43–47°. There are a spread of W–N bond distances ranging from 2.06–2.12 Å. In the second W4+ site, W4+ is bonded to six N3- atoms to form distorted WN6 pentagonal pyramids that share corners with ten FeN6 octahedra, edges with six WN6 pentagonal pyramids, and a faceface with one FeN6 octahedra. The corner-sharing octahedra tilt angles range from 45–47°. There are a spread of W–N bond distances ranging from 2.06–2.18 Å. There are two inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six N3- atoms to form FeN6 octahedra that share corners with twelve WN6 pentagonal pyramids, edges with two equivalent FeN6 octahedra, and faces with two equivalent WN6 pentagonal pyramids. There are two shorter (1.96 Å) and four longer (2.08 Å) Fe–N bond lengths. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six N3- atoms to form FeN6 octahedra that share corners with twelve WN6 pentagonal pyramids, edges with six equivalent FeN6 octahedra, and faces with two WN6 pentagonal pyramids. There are a spread of Fe–N bond distances ranging from 2.07–2.37 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a 6-coordinate geometry to three W4+ and three equivalent Fe+2.67+ atoms. In the second N3- site, N3- is bonded in a 6-coordinate geometry to three W4+ and three equivalent Fe+2.67+ atoms. In the third N3- site, N3- is bonded in a rectangular see-saw-like geometry to three W4+ and one Fe+2.67+ atom. In the fourth N3- site, N3- is bonded in a 5-coordinate geometry to three W4+ and two equivalent Fe+2.67+ atoms.