Materials Data on K9Fe2S7 by Materials Project
K9Fe2S7 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of K–S bond distances ranging from 3.33–3.46 Å. In the second K1+ site, K1+ is bonded to six S2- atoms to form distorted KS6 octahedra that share corners with three equivalent KS5 square pyramids, corners with three equivalent FeS4 tetrahedra, and faces with three equivalent KS5 square pyramids. There are three shorter (3.22 Å) and three longer (3.45 Å) K–S bond lengths. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are three shorter (3.24 Å) and three longer (3.41 Å) K–S bond lengths. In the fourth K1+ site, K1+ is bonded to five S2- atoms to form distorted KS5 square pyramids that share a cornercorner with one KS6 octahedra, corners with six equivalent KS5 square pyramids, a cornercorner with one FeS4 tetrahedra, an edgeedge with one FeS4 tetrahedra, and a faceface with one KS6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are a spread of K–S bond distances ranging from 3.07–3.28 Å. In the fifth K1+ site, K1+ is bonded in a distorted T-shaped geometry to three equivalent S2- atoms. All K–S bond lengths are 3.18 Å. There are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with three equivalent KS6 octahedra, corners with three equivalent KS5 square pyramids, and edges with three equivalent KS5 square pyramids. The corner-sharing octahedral tilt angles are 44°. There are three shorter (2.31 Å) and one longer (2.36 Å) Fe–S bond lengths. In the second Fe+2.50+ site, Fe+2.50+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All Fe–S bond lengths are 2.23 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 7-coordinate geometry to six K1+ and one Fe+2.50+ atom. In the second S2- site, S2- is bonded in a 1-coordinate geometry to six K1+ and one Fe+2.50+ atom. In the third S2- site, S2- is bonded in a 1-coordinate geometry to seven K1+ and one Fe+2.50+ atom.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). LBNL Materials Project
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Contributing Organization:
- MIT; UC Berkeley; Duke; U Louvain
- DOE Contract Number:
- AC02-05CH11231; EDCBEE
- OSTI ID:
- 1190950
- Report Number(s):
- mp-14889
- Resource Relation:
- Related Information: https://materialsproject.org/citing
- Country of Publication:
- United States
- Language:
- English
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