DOI: 10.17188/1286013
title: Materials Data on Fe8O9 by Materials Project

description: Fe8O9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Fe+2.25+ sites. In the first Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. There are a spread of Fe–O bond distances ranging from 2.17–2.25 Å. In the second Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 6–10°. There are a spread of Fe–O bond distances ranging from 2.00–2.13 Å. In the third Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–12°. There are a spread of Fe–O bond distances ranging from 2.15–2.26 Å. In the fourth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–11°. There are a spread of Fe–O bond distances ranging from 2.00–2.12 Å. In the fifth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Fe–O bond distances ranging from 2.13–2.30 Å. In the sixth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–13°. There are a spread of Fe–O bond distances ranging from 2.12–2.23 Å. In the seventh Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–12°. There are a spread of Fe–O bond distances ranging from 2.12–2.26 Å. In the eighth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–11°. There are a spread of Fe–O bond distances ranging from 2.12–2.25 Å. In the ninth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–11°. There are a spread of Fe–O bond distances ranging from 2.15–2.29 Å. In the tenth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–12°. There are a spread of Fe–O bond distances ranging from 2.08–2.23 Å. In the eleventh Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–13°. There are a spread of Fe–O bond distances ranging from 2.00–2.10 Å. In the twelfth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–13°. There are a spread of Fe–O bond distances ranging from 1.99–2.12 Å. In the thirteenth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–12°. There are a spread of Fe–O bond distances ranging from 2.15–2.29 Å. In the fourteenth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–15°. There are a spread of Fe–O bond distances ranging from 2.07–2.28 Å. In the fifteenth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–15°. There are a spread of Fe–O bond distances ranging from 2.16–2.26 Å. In the sixteenth Fe+2.25+ site, Fe+2.25+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–13°. There are a spread of Fe–O bond distances ranging from 2.10–2.25 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with two equivalent OFe6 octahedra, corners with seven OFe5 square pyramids, edges with five OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 6–7°. In the second O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with three OFe6 octahedra, corners with six OFe5 square pyramids, edges with three OFe6 octahedra, and edges with five OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–6°. In the third O2- site, O2- is bonded to six Fe+2.25+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with two OFe6 octahedra, and edges with ten OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 1–9°. In the fourth O2- site, O2- is bonded to five Fe+2.25+ 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 fifth O2- site, O2- is bonded to five Fe+2.25+ 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 six Fe+2.25+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with two OFe6 octahedra, and edges with ten OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 1–7°. In the seventh O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with three OFe6 octahedra, corners with six OFe5 square pyramids, edges with three OFe6 octahedra, and edges with five OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–4°. In the eighth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with five OFe6 octahedra, and edges with three OFe5 square pyramids. In the ninth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with two equivalent OFe6 octahedra, corners with seven OFe5 square pyramids, edges with five OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedral tilt angles are 7°. In the tenth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with two OFe6 octahedra, corners with seven OFe5 square pyramids, edges with five OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 7–9°. In the eleventh O2- site, O2- is bonded to six Fe+2.25+ atoms to form OFe6 octahedra that share a cornercorner with one OFe6 octahedra, corners with five OFe5 square pyramids, edges with three OFe6 octahedra, and edges with nine OFe5 square pyramids. The corner-sharing octahedral tilt angles are 5°. In the twelfth O2- site, O2- is bonded to six Fe+2.25+ atoms to form OFe6 octahedra that share corners with two equivalent OFe6 octahedra, corners with four OFe5 square pyramids, edges with five OFe6 octahedra, and edges with seven OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 7–9°. In the thirteenth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with three OFe6 octahedra, corners with six OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–6°. In the fourteenth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with three OFe6 octahedra, corners with six OFe5 square pyramids, edges with four OFe6 octahedra, and edges with four OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–9°. In the fifteenth O2- site, O2- is bonded to six Fe+2.25+ atoms to form OFe6 octahedra that share corners with two equivalent OFe6 octahedra, corners with four OFe5 square pyramids, edges with five OFe6 octahedra, and edges with seven OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 6–7°. In the sixteenth O2- site, O2- is bonded to six Fe+2.25+ atoms to form OFe6 octahedra that share a cornercorner with one OFe6 octahedra, corners with five OFe5 square pyramids, edges with three OFe6 octahedra, and edges with nine OFe5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the seventeenth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with two OFe6 octahedra, corners with seven OFe5 square pyramids, edges with five OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 7–9°. In the eighteenth O2- site, O2- is bonded to five Fe+2.25+ atoms to form OFe5 square pyramids that share corners with nine OFe5 square pyramids, edges with five OFe6 octahedra, and edges with three OFe5 square pyramids.