Materials Data on BaYFe2O5 by Materials Project
YBaFe2O5 crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight FeO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.82–3.17 Å. Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Y–O bond lengths are 2.44 Å. There are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to five O2- atoms to form distorted FeO5 square pyramids that share corners with five FeO5 square pyramids and faces with four equivalent BaO12 cuboctahedra. There are a spread of Fe–O bond distances ranging from 1.92–2.03 Å. In the second Fe+2.50+ site, Fe+2.50+ is bonded to five O2- atoms to form FeO5 square pyramids that share corners with five FeO5 square pyramids and faces with four equivalent BaO12 cuboctahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.28 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Y3+, and two Fe+2.50+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Y3+, and two equivalent Fe+2.50+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Y3+, and two equivalent Fe+2.50+ atoms. In the fourth O2- site, O2- is bonded to four equivalent Ba2+ and two Fe+2.50+ atoms to form a mixture of distorted edge and corner-sharing OBa4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°.