DOE OSTI2020
Fe7O8 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Fe+2.29+ sites. In the first Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 7–10°. There are a spread of Fe–O bond distances ranging from 2.15–2.22 Å. In the second Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–9°. There are a spread of Fe–O bond distances ranging from 2.13–2.27 Å. In the third Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 6–10°. There are a spread of Fe–O bond distances ranging from 2.14–2.21 Å. In the fourth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–11°. There are a spread of Fe–O bond distances ranging from 2.14–2.22 Å. In the fifth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 6–9°. There are a spread of Fe–O bond distances ranging from 2.17–2.20 Å. In the sixth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–11°. There are a spread of Fe–O bond distances ranging from 2.17–2.21 Å. In the seventh Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–8°. There are a spread of Fe–O bond distances ranging from 2.06–2.16 Å. In the eighth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. There are a spread of Fe–O bond distances ranging from 2.08–2.14 Å. In the ninth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–10°. There are a spread of Fe–O bond distances ranging from 2.10–2.29 Å. In the tenth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–10°. There are a spread of Fe–O bond distances ranging from 2.09–2.30 Å. In the eleventh Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. There are a spread of Fe–O bond distances ranging from 2.19–2.32 Å. In the twelfth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–8°. There are a spread of Fe–O bond distances ranging from 2.19–2.32 Å. In the thirteenth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are three shorter (2.04 Å) and three longer (2.05 Å) Fe–O bond lengths. In the fourteenth Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are four shorter (2.04 Å) and two longer (2.05 Å) Fe–O bond lengths. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded to six Fe+2.29+ atoms to form OFe6 octahedra that share corners with six OFe6 octahedra and edges with twelve OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the second O2- site, O2- is bonded to six Fe+2.29+ atoms to form OFe6 octahedra that share corners with six OFe6 octahedra and edges with twelve OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the third O2- site, O2- is bonded to six Fe+2.29+ atoms to form OFe6 octahedra that share corners with six OFe6 octahedra and edges with twelve OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the fourth O2- site, O2- is bonded to six Fe+2.29+ atoms to form OFe6 octahedra that share corners with six OFe6 octahedra and edges with twelve OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the fifth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the sixth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the seventh O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the eighth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the ninth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the tenth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the eleventh O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the twelfth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the thirteenth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the fourteenth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the fifteenth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. In the sixteenth O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids.