Materials Data on Fe5O7 by Materials Project

Fe5O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Fe+2.80+ sites. In the first Fe+2.80+ site, Fe+2.80+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four equivalent FeO7 pentagonal bipyramids, edges with two equivalent FeO6 octahedra, and edges with six equivalent FeO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 56°. There are two shorter (2.03 Å) and four longer (2.05 Å) Fe–O bond lengths. In the second Fe+2.80+ site, Fe+2.80+ is bonded to seven O2- atoms to form distorted FeO7 pentagonal bipyramids that share corners with eight FeO6 octahedra, edges with four FeO6 octahedra, edges with two equivalent FeO7 pentagonal bipyramids, and faces with two equivalent FeO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 19–68°. There are a spread of Fe–O bond distances ranging from 2.07–2.39 Å. In the third Fe+2.80+ site, Fe+2.80+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three FeO6 octahedra, corners with six equivalent FeO7 pentagonal bipyramids, edges with five equivalent FeO6 octahedra, and an edgeedge with one FeO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 0–56°. There are a spread of Fe–O bond distances ranging from 1.99–2.12 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Fe+2.80+ atoms to form distorted OFe4 tetrahedra that share corners with four equivalent OFe5 square pyramids, corners with three equivalent OFe4 tetrahedra, and edges with three equivalent OFe5 square pyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to five Fe+2.80+ atoms. In the third O2- site, O2- is bonded to five Fe+2.80+ atoms to form distorted OFe5 square pyramids that share corners with two equivalent OFe5 square pyramids, corners with four equivalent OFe4 tetrahedra, edges with five equivalent OFe5 square pyramids, and edges with three equivalent OFe4 tetrahedra. In the fourth O2- site, O2- is bonded in a square co-planar geometry to four equivalent Fe+2.80+ atoms.