Fe5O8 is beta indium sulfide-like structured and crystallizes in the cubic F-43m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form FeO6 octahedra that share corners with three equivalent Fe(2)O4 tetrahedra and edges with six equivalent Fe(1)O6 octahedra. In the second Fe site, Fe(2) is bonded to four equivalent O(1) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. There are two inequivalent O sites. In the first O site, O(2) is bonded in a distorted T-shaped geometry to three equivalent Fe(1) atoms. In the second O site, O(1) is bonded to one Fe(2) and three equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing OFe4 trigonal pyramids.
Fe5O8 is beta indium sulfide-like structured and crystallizes in the cubic F-43m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form FeO6 octahedra that share corners with three equivalent Fe(2)O4 tetrahedra and edges with six equivalent Fe(1)O6 octahedra. All Fe(1)-O(1) bond lengths are 2.10 Å. All Fe(1)-O(2) bond lengths are 1.98 Å. In the second Fe site, Fe(2) is bonded to four equivalent O(1) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. All Fe(2)-O(1) bond lengths are 1.95 Å. There are two inequivalent O sites. In the first O site, O(2) is bonded in a distorted T-shaped geometry to three equivalent Fe(1) atoms. In the second O site, O(1) is bonded to one Fe(2) and three equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing OFe4 trigonal pyramids.