Materials Data on Ba4Y2O7 by Materials Project
Ba4Y2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are six inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.73–3.39 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.57–3.11 Å. In the third Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.60–3.18 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.61–2.98 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ba–O bond distances ranging from 2.54–2.93 Å. In the sixth Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.61–3.39 Å. There are three inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to four O2- atoms to form corner-sharing YO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.10–2.20 Å. In the second Y3+ site, Y3+ is bonded to four O2- atoms to form YO4 trigonal pyramids that share a cornercorner with one YO4 tetrahedra and a cornercorner with one YO5 trigonal bipyramid. There are a spread of Y–O bond distances ranging from 2.11–2.23 Å. In the third Y3+ site, Y3+ is bonded to five O2- atoms to form YO5 trigonal bipyramids that share a cornercorner with one YO5 trigonal bipyramid and a cornercorner with one YO4 trigonal pyramid. There are a spread of Y–O bond distances ranging from 2.16–2.55 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ba2+ and two equivalent Y3+ atoms to form distorted OBa4Y2 octahedra that share corners with four equivalent OBa3Y tetrahedra and faces with two equivalent OBa4Y2 octahedra. In the second O2- site, O2- is bonded to three Ba2+ and one Y3+ atom to form distorted corner-sharing OBa3Y trigonal pyramids. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Ba2+ and one Y3+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four Ba2+ and one Y3+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+ and two Y3+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Y3+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Y3+ atom. In the eighth O2- site, O2- is bonded to four Ba2+ and two Y3+ atoms to form distorted OBa4Y2 octahedra that share edges with two equivalent OBa3Y tetrahedra and a faceface with one OBa4Y2 octahedra. In the ninth O2- site, O2- is bonded to three Ba2+ and one Y3+ atom to form OBa3Y tetrahedra that share corners with two equivalent OBa4Y2 octahedra, corners with two equivalent OBa3Y tetrahedra, and edges with two equivalent OBa4Y2 octahedra. The corner-sharing octahedra tilt angles range from 39–67°. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ba2+ and one Y3+ atom. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to four Ba2+ and one Y3+ atom.