Materials Data on Ba2Co2O5 by Materials Project
Ba2Co2O5 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 2.69–3.07 Å. There are two inequivalent Co3+ sites. In the first Co3+ site, Co3+ is bonded in a distorted square co-planar geometry to four equivalent O2- atoms. All Co–O bond lengths are 2.01 Å. In the second Co3+ site, Co3+ is bonded to four O2- atoms to form corner-sharing CoO4 tetrahedra. There are a spread of Co–O bond distances ranging from 1.78–1.92 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ba2+ and two equivalent Co3+ atoms to form a mixture of distorted face, edge, and corner-sharing OBa4Co2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ba2+ and one Co3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and two equivalent Co3+ atoms.