Materials Data on Ba8Cu8O19 by Materials Project
Ba8Cu8O19 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.71–3.13 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.83–3.09 Å. In the third Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–2.98 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.69–2.99 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–3.26 Å. In the sixth Ba2+ site, Ba2+ is bonded to eight O2- atoms to form distorted BaO8 hexagonal bipyramids that share corners with four CuO5 square pyramids, a cornercorner with one CuO4 tetrahedra, an edgeedge with one CuO5 square pyramid, an edgeedge with one CuO4 tetrahedra, and a faceface with one CuO5 square pyramid. There are a spread of Ba–O bond distances ranging from 2.73–2.98 Å. In the seventh Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.70–2.92 Å. In the eighth Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–3.07 Å. There are eight inequivalent Cu+2.75+ sites. In the first Cu+2.75+ site, Cu+2.75+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one CuO5 square pyramid, an edgeedge with one CuO5 square pyramid, and a faceface with one BaO8 hexagonal bipyramid. There are a spread of Cu–O bond distances ranging from 1.83–2.22 Å. In the second Cu+2.75+ site, Cu+2.75+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one BaO8 hexagonal bipyramid, corners with three CuO5 square pyramids, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.84–2.16 Å. In the third Cu+2.75+ site, Cu+2.75+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with two equivalent BaO8 hexagonal bipyramids and corners with three CuO5 square pyramids. There are a spread of Cu–O bond distances ranging from 1.84–2.20 Å. In the fourth Cu+2.75+ site, Cu+2.75+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.82–1.93 Å. In the fifth Cu+2.75+ site, Cu+2.75+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one BaO8 hexagonal bipyramid, corners with three CuO5 square pyramids, and an edgeedge with one CuO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.85–2.18 Å. In the sixth Cu+2.75+ site, Cu+2.75+ is bonded to four O2- atoms to form CuO4 tetrahedra that share a cornercorner with one BaO8 hexagonal bipyramid, corners with two equivalent CuO5 square pyramids, an edgeedge with one BaO8 hexagonal bipyramid, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.88–2.00 Å. In the seventh Cu+2.75+ site, Cu+2.75+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one CuO5 square pyramid, corners with two equivalent CuO4 tetrahedra, an edgeedge with one BaO8 hexagonal bipyramid, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.88–2.19 Å. In the eighth Cu+2.75+ site, Cu+2.75+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing CuO5 square pyramids. There are a spread of Cu–O bond distances ranging from 1.85–2.17 Å. There are nineteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the third O2- site, O2- is bonded in a distorted L-shaped geometry to four Ba2+ and two Cu+2.75+ atoms. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the eighth O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the ninth O2- site, O2- is bonded to four Ba2+ and two Cu+2.75+ atoms to form distorted corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedra tilt angles range from 5–9°. In the tenth O2- site, O2- is bonded in a distorted L-shaped geometry to four Ba2+ and two Cu+2.75+ atoms. In the eleventh O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the fifteenth O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the seventeenth O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Cu+2.75+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted L-shaped geometry to four Ba2+ and two Cu+2.75+ atoms. In the nineteenth O2- site, O2- is bonded to four Ba2+ and two Cu+2.75+ atoms to form distorted corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedra tilt angles range from 5–9°.