Materials Data on Ba2Fe2O5 by Materials Project
Ba2Fe2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.63–3.27 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with two equivalent FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. There are a spread of Fe–O bond distances ranging from 2.07–2.31 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with two equivalent FeO6 octahedra and corners with two equivalent FeO4 tetrahedra. The corner-sharing octahedral tilt angles are 26°. All Fe–O bond lengths are 1.92 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ba2+ and two equivalent Fe3+ atoms to form distorted OBa4Fe2 octahedra that share corners with two equivalent OBa4Fe2 octahedra, corners with four equivalent OBa2Fe2 tetrahedra, edges with two equivalent OBa4Fe2 octahedra, and faces with four equivalent OBa4Fe2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Ba2+ and two Fe3+ atoms. In the third O2- site, O2- is bonded to two equivalent Ba2+ and two equivalent Fe3+ atoms to form distorted OBa2Fe2 tetrahedra that share corners with eight equivalent OBa4Fe2 octahedra and corners with two equivalent OBa2Fe2 tetrahedra. The corner-sharing octahedra tilt angles range from 16–81°.