Materials Data on Ba2ErCoCu2O7 by Materials Project
Ba2ErCoCu2O7 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–3.03 Å. Er3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.40 Å) and four longer (2.42 Å) Er–O bond lengths. Co3+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.81 Å) and two longer (1.96 Å) Co–O bond length. Cu2+ is bonded to five O2- atoms to form corner-sharing CuO5 square pyramids. There are a spread of Cu–O bond distances ranging from 1.95–2.44 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 Er3+, and two equivalent Cu2+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Ba2+, one Co3+, and one Cu2+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Er3+, and two equivalent Cu2+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Co3+ atoms.