Materials Data on Fe7S12 by Materials Project
Fe7S12 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are fourteen inequivalent Fe+2.86+ sites. In the first Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four equivalent FeS6 octahedra and corners with five FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 62–65°. There are a spread of Fe–S bond distances ranging from 2.12–2.32 Å. In the second Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four FeS6 octahedra and corners with six FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 62–66°. There are a spread of Fe–S bond distances ranging from 2.11–2.36 Å. In the third Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four equivalent FeS6 octahedra and corners with six FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 62–65°. There are a spread of Fe–S bond distances ranging from 2.13–2.30 Å. In the fourth Fe+2.86+ site, Fe+2.86+ is bonded to six S+1.67- atoms to form corner-sharing FeS6 octahedra. There are a spread of Fe–S bond distances ranging from 2.22–2.26 Å. In the fifth Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four FeS6 octahedra and corners with six FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 61–64°. There are a spread of Fe–S bond distances ranging from 2.12–2.34 Å. In the sixth Fe+2.86+ site, Fe+2.86+ is bonded to six S+1.67- atoms to form corner-sharing FeS6 octahedra. There are a spread of Fe–S bond distances ranging from 2.22–2.27 Å. In the seventh Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with two equivalent FeS6 octahedra and corners with seven FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 63–65°. There are a spread of Fe–S bond distances ranging from 2.13–2.27 Å. In the eighth Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with two equivalent FeS6 octahedra and corners with five FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 62–65°. There are a spread of Fe–S bond distances ranging from 2.14–2.35 Å. In the ninth Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four FeS6 octahedra and corners with six FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 61–64°. There are a spread of Fe–S bond distances ranging from 2.12–2.34 Å. In the tenth Fe+2.86+ site, Fe+2.86+ is bonded to six S+1.67- atoms to form corner-sharing FeS6 octahedra. There are a spread of Fe–S bond distances ranging from 2.22–2.26 Å. In the eleventh Fe+2.86+ site, Fe+2.86+ is bonded in a rectangular see-saw-like geometry to four S+1.67- atoms. There are a spread of Fe–S bond distances ranging from 2.12–2.28 Å. In the twelfth Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with two equivalent FeS6 octahedra and corners with seven FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 64–65°. There are a spread of Fe–S bond distances ranging from 2.12–2.39 Å. In the thirteenth Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four equivalent FeS6 octahedra and corners with six FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 61–65°. There are a spread of Fe–S bond distances ranging from 2.14–2.30 Å. In the fourteenth Fe+2.86+ site, Fe+2.86+ is bonded to five S+1.67- atoms to form FeS5 square pyramids that share corners with four FeS6 octahedra and corners with six FeS5 square pyramids. The corner-sharing octahedra tilt angles range from 62–66°. There are a spread of Fe–S bond distances ranging from 2.12–2.36 Å. There are twenty-four inequivalent S+1.67- sites. In the first S+1.67- site, S+1.67- is bonded in a 4-coordinate geometry to three Fe+2.86+ and one S+1.67- atom. The S–S bond length is 2.19 Å. In the second S+1.67- site, S+1.67- is bonded in a 4-coordinate geometry to three Fe+2.86+ and one S+1.67- atom. The S–S bond length is 2.18 Å. In the third S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the fourth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the fifth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the sixth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the seventh S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the eighth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the ninth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the tenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the eleventh S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the twelfth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the thirteenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the fourteenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the fifteenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the sixteenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the seventeenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the eighteenth S+1.67- site, S+1.67- is bonded in a trigonal non-coplanar geometry to three Fe+2.86+ atoms. In the nineteenth S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ atoms. In the twentieth S+1.67- site, S+1.67- is bonded in a trigonal non-coplanar geometry to three Fe+2.86+ atoms. In the twenty-first S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ and one S+1.67- atom. In the twenty-second S+1.67- site, S+1.67- is bonded in a 3-coordinate geometry to three Fe+2.86+ and one S+1.67- atom. In the twenty-third S+1.67- site, S+1.67- is bonded in a trigonal non-coplanar geometry to three Fe+2.86+ atoms. In the twenty-fourth S+1.67- site, S+1.67- is bonded in a trigonal non-coplanar geometry to three Fe+2.86+ atoms.