Materials Data on Fe2O3 by Materials Project

Abstract

Fe2O3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Fe–O bond distances ranging from 1.91–2.15 Å. In the second Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.83–2.53 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to six Fe3+ atoms to form distorted OFe6 octahedra that share corners with four equivalent OFe5 square pyramids, edges with two equivalent OFe6 octahedra, and edges with six equivalent OFe5 square pyramids. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Fe3+ atoms. In the third O2- site, O2- is bonded to five Fe3+ atoms to form distorted OFe5 square pyramids that share corners with two equivalent OFe6 octahedra, edges with three equivalent OFe6 octahedra, and edges with four equivalent OFe5 square pyramids. The corner-sharing octahedral tilt angles are 9°. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Fe3+ atoms.