Materials Data on Fe3Mo5N8 by Materials Project
Mo5Fe3N8 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Mo3+ sites. In the first Mo3+ site, Mo3+ is bonded to six N3- atoms to form distorted MoN6 pentagonal pyramids that share corners with four equivalent MoN6 octahedra, corners with eight FeN6 octahedra, edges with six MoN6 pentagonal pyramids, and faces with two FeN6 octahedra. The corner-sharing octahedra tilt angles range from 45–46°. There are a spread of Mo–N bond distances ranging from 2.12–2.15 Å. In the second Mo3+ site, Mo3+ is bonded to six N3- atoms to form distorted MoN6 pentagonal pyramids that share corners with two equivalent MoN6 octahedra, corners with ten FeN6 octahedra, edges with six MoN6 pentagonal pyramids, a faceface with one MoN6 octahedra, and a faceface with one FeN6 octahedra. The corner-sharing octahedra tilt angles range from 44–47°. There are a spread of Mo–N bond distances ranging from 2.11–2.14 Å. In the third Mo3+ site, Mo3+ is bonded to six N3- atoms to form MoN6 octahedra that share corners with twelve MoN6 pentagonal pyramids, edges with two equivalent MoN6 octahedra, edges with four equivalent FeN6 octahedra, and faces with two equivalent MoN6 pentagonal pyramids. There are two shorter (2.18 Å) and four longer (2.21 Å) Mo–N bond lengths. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six N3- atoms to form FeN6 octahedra that share corners with twelve MoN6 pentagonal pyramids, edges with two equivalent FeN6 octahedra, edges with four equivalent MoN6 octahedra, and faces with two equivalent MoN6 pentagonal pyramids. There are two shorter (2.20 Å) and four longer (2.22 Å) Fe–N bond lengths. In the second Fe3+ site, Fe3+ is bonded to six N3- atoms to form FeN6 octahedra that share corners with twelve MoN6 pentagonal pyramids, edges with six equivalent FeN6 octahedra, and faces with two MoN6 pentagonal pyramids. There are a spread of Fe–N bond distances ranging from 2.09–2.14 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to four Mo3+ and two equivalent Fe3+ atoms to form distorted NFe2Mo4 pentagonal pyramids that share corners with nine NFe2Mo4 pentagonal pyramids, edges with nine NFe2Mo4 pentagonal pyramids, and a faceface with one NFe3Mo3 pentagonal pyramid. In the second N3- site, N3- is bonded to five Mo3+ and one Fe3+ atom to form distorted NFeMo5 pentagonal pyramids that share corners with nine NFeMo5 pentagonal pyramids, edges with nine NFe2Mo4 pentagonal pyramids, and a faceface with one NFe3Mo3 pentagonal pyramid. In the third N3- site, N3- is bonded to three Mo3+ and three equivalent Fe3+ atoms to form distorted NFe3Mo3 pentagonal pyramids that share corners with nine NFe2Mo4 pentagonal pyramids, edges with nine NFe3Mo3 pentagonal pyramids, and a faceface with one NFeMo5 pentagonal pyramid. In the fourth N3- site, N3- is bonded to three Mo3+ and three equivalent Fe3+ atoms to form distorted NFe3Mo3 pentagonal pyramids that share corners with nine NFe2Mo4 pentagonal pyramids, edges with nine NFe3Mo3 pentagonal pyramids, and a faceface with one NFe2Mo4 pentagonal pyramid.