Materials Data on Fe5O8 by Materials Project

Fe5O8 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to four O atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–57°. There is three shorter (1.90 Å) and one longer (1.97 Å) Fe–O bond length. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra and edges with four equivalent FeO6 octahedra. There are four shorter (2.02 Å) and two longer (2.07 Å) Fe–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three Fe atoms. In the second O site, O is bonded in a distorted rectangular see-saw-like geometry to four Fe atoms.