DOI: 10.17188/1679935
title: Materials Data on BaCa2Er10O18 by Materials Project

description: BaCa2Er10O18 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first 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 2.81–3.09 Å. In the second 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 2.72–3.04 Å. There are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to seven O2- atoms to form distorted CaO7 pentagonal bipyramids that share corners with ten ErO6 octahedra, edges with four ErO6 octahedra, a faceface with one ErO6 octahedra, and faces with two equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 15–77°. There are a spread of Ca–O bond distances ranging from 2.44–2.60 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.45–2.55 Å. In the third Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.43–2.55 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.48–2.53 Å. There are twenty inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with four ErO6 octahedra, edges with four ErO6 octahedra, and edges with two equivalent ErO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 52°. There are a spread of Er–O bond distances ranging from 2.15–2.39 Å. In the second Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, edges with four ErO6 octahedra, and edges with two equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Er–O bond distances ranging from 2.17–2.40 Å. In the third Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, edges with four ErO6 octahedra, and edges with two equivalent ErO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Er–O bond distances ranging from 2.19–2.37 Å. In the fourth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent CaO7 pentagonal bipyramids, edges with four ErO6 octahedra, and an edgeedge with one CaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 51–63°. There are a spread of Er–O bond distances ranging from 2.20–2.33 Å. In the fifth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, edges with four ErO6 octahedra, and an edgeedge with one ErO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Er–O bond distances ranging from 2.16–2.45 Å. In the sixth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, edges with four ErO6 octahedra, and an edgeedge with one ErO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Er–O bond distances ranging from 2.17–2.43 Å. In the seventh Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent CaO7 pentagonal bipyramids, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 54–62°. There are a spread of Er–O bond distances ranging from 2.24–2.34 Å. In the eighth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Er–O bond distances ranging from 2.22–2.32 Å. In the ninth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Er–O bond distances ranging from 2.19–2.35 Å. In the tenth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, edges with four ErO6 octahedra, and an edgeedge with one ErO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Er–O bond distances ranging from 2.16–2.43 Å. In the eleventh Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent CaO7 pentagonal bipyramids, edges with four ErO6 octahedra, and an edgeedge with one CaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Er–O bond distances ranging from 2.20–2.31 Å. In the twelfth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, edges with four ErO6 octahedra, and an edgeedge with one ErO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Er–O bond distances ranging from 2.15–2.43 Å. In the thirteenth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Er–O bond distances ranging from 2.23–2.31 Å. In the fourteenth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Er–O bond distances ranging from 2.20–2.33 Å. In the fifteenth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent CaO7 pentagonal bipyramids, and edges with four ErO6 octahedra. The corner-sharing octahedra tilt angles range from 53–63°. There are a spread of Er–O bond distances ranging from 2.19–2.32 Å. In the sixteenth Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, edges with four ErO6 octahedra, and a faceface with one ErO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Er–O bond distances ranging from 2.13–2.51 Å. In the seventeenth Er3+ site, Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent ErO7 pentagonal bipyramids, edges with four ErO6 octahedra, and a faceface with one ErO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Er–O bond distances ranging from 2.15–2.49 Å. In the eighteenth Er3+ site, Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with four ErO6 octahedra, corners with two equivalent CaO7 pentagonal bipyramids, edges with four ErO6 octahedra, and a faceface with one CaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 51–52°. There are a spread of Er–O bond distances ranging from 2.18–2.38 Å. In the nineteenth Er3+ site, Er3+ is bonded to seven O2- atoms to form distorted ErO7 pentagonal bipyramids that share corners with ten ErO6 octahedra, edges with four ErO6 octahedra, a faceface with one ErO6 octahedra, and faces with two equivalent ErO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 14–74°. There are a spread of Er–O bond distances ranging from 2.34–2.50 Å. In the twentieth Er3+ site, Er3+ is bonded to seven O2- atoms to form distorted ErO7 pentagonal bipyramids that share corners with ten ErO6 octahedra, edges with four ErO6 octahedra, a faceface with one ErO6 octahedra, and faces with two equivalent ErO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 13–75°. There are a spread of Er–O bond distances ranging from 2.35–2.50 Å. There are thirty-six inequivalent O2- sites. In the first O2- site, O2- is bonded to five Er3+ atoms to form distorted OEr5 trigonal bipyramids that share corners with two equivalent OEr5 square pyramids, corners with two equivalent OEr5 trigonal bipyramids, an edgeedge with one OEr5 square pyramid, edges with five OEr5 trigonal bipyramids, and edges with two equivalent OEr4 trigonal pyramids. In the second O2- site, O2- is bonded to two equivalent Ca2+ and three Er3+ atoms to form distorted OCa2Er3 trigonal bipyramids that share corners with two equivalent OCa2Er3 square pyramids, corners with two equivalent OCa2Er3 trigonal bipyramids, edges with three OCa2Er3 square pyramids, edges with three OCa2Er3 trigonal bipyramids, and edges with two equivalent OCaEr3 trigonal pyramids. In the third O2- site, O2- is bonded in a 5-coordinate geometry to five Er3+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Ca2+ and three Er3+ atoms to form distorted OCa2Er3 trigonal bipyramids that share corners with four OCa2Er3 square pyramids, a cornercorner with one OEr4 trigonal pyramid, edges with two OCa2Er3 square pyramids, and edges with four OCa2Er3 trigonal bipyramids. In the fifth O2- site, O2- is bonded to two equivalent Ca2+ and three Er3+ atoms to form distorted OCa2Er3 square pyramids that share corners with two equivalent OCa2Er3 square pyramids, corners with two equivalent OCa2Er3 trigonal bipyramids, a cornercorner with one OCaEr3 trigonal pyramid, edges with three OCa2Er3 square pyramids, and edges with three OCa2Er3 trigonal bipyramids. In the sixth O2- site, O2- is bonded to two equivalent Ca2+ and three Er3+ atoms to form distorted OCa2Er3 trigonal bipyramids that share corners with four OCa2Er3 trigonal bipyramids, a cornercorner with one OEr4 trigonal pyramid, and edges with four OCa2Er3 trigonal bipyramids. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Er3+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Er3+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Er3+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Er3+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Er3+ atoms. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Er3+ atoms. In the thirteenth O2- site, O2- is bonded in a trigonal planar geometry to three Er3+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Er3+ atoms. In the fifteenth O2- site, O2- is bonded in a trigonal planar geometry to three Er3+ atoms. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Er3+ atoms. In the seventeenth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Er3+ atoms. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Er3+ atoms.