DOI: 10.17188/1745474
title: Materials Data on SrCa3Yb9O18 by Materials Project

description: SrCa3Yb9O18 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Sr is bonded in a 6-coordinate geometry to six O atoms. There are three shorter (2.53 Å) and three longer (2.57 Å) Sr–O bond lengths. Ca is bonded to seven O atoms to form distorted CaO7 pentagonal bipyramids that share corners with ten YbO6 octahedra, edges with four YbO6 octahedra, a faceface with one YbO6 octahedra, and faces with two equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 9–81°. There are a spread of Ca–O bond distances ranging from 2.43–2.50 Å. There are three inequivalent Yb sites. In the first Yb site, Yb is bonded to six O atoms to form YbO6 octahedra that share corners with four equivalent YbO6 octahedra, corners with four equivalent CaO7 pentagonal bipyramids, edges with four YbO6 octahedra, and an edgeedge with one CaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 60–62°. There are a spread of Yb–O bond distances ranging from 2.23–2.39 Å. In the second Yb site, Yb is bonded to six O atoms to form YbO6 octahedra that share corners with four equivalent YbO6 octahedra, corners with two equivalent CaO7 pentagonal bipyramids, edges with four YbO6 octahedra, edges with two equivalent CaO7 pentagonal bipyramids, and a faceface with one CaO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 50°. There are a spread of Yb–O bond distances ranging from 2.26–2.39 Å. In the third Yb site, Yb is bonded to six O atoms to form distorted YbO6 octahedra that share corners with four equivalent YbO6 octahedra, corners with four equivalent CaO7 pentagonal bipyramids, edges with four equivalent YbO6 octahedra, and an edgeedge with one CaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 60–62°. There are a spread of Yb–O bond distances ranging from 2.23–2.42 Å. There are six inequivalent O sites. In the first O site, O is bonded to one Sr and three Yb atoms to form distorted OSrYb3 trigonal pyramids that share corners with five OCa2Yb3 square pyramids, corners with two equivalent OCa2Yb3 trigonal bipyramids, corners with seven OSrYb3 trigonal pyramids, an edgeedge with one OCa2Yb3 square pyramid, and edges with two equivalent OSrYb3 trigonal pyramids. In the second O site, O is bonded to two equivalent Ca and three equivalent Yb atoms to form OCa2Yb3 square pyramids that share corners with two equivalent OCa2Yb3 square pyramids, corners with two equivalent OCa2Yb3 trigonal bipyramids, corners with nine OSrYb3 trigonal pyramids, edges with five OCa2Yb3 square pyramids, an edgeedge with one OCa2Yb3 trigonal bipyramid, and an edgeedge with one OSrYb3 trigonal pyramid. In the third O site, O is bonded to one Ca and three equivalent Yb atoms to form OCaYb3 trigonal pyramids that share corners with three OCa2Yb3 square pyramids, corners with two equivalent OCa2Yb3 trigonal bipyramids, corners with six equivalent OCaYb3 trigonal pyramids, edges with two equivalent OCa2Yb3 square pyramids, and edges with three equivalent OCa2Yb3 trigonal bipyramids. In the fourth O site, O is bonded to two equivalent Ca and three Yb atoms to form distorted OCa2Yb3 square pyramids that share corners with two equivalent OCa2Yb3 square pyramids, corners with two equivalent OCa2Yb3 trigonal bipyramids, corners with five OSrYb3 trigonal pyramids, edges with three OCa2Yb3 square pyramids, edges with three equivalent OCa2Yb3 trigonal bipyramids, and edges with three OSrYb3 trigonal pyramids. In the fifth O site, O is bonded to two equivalent Ca and three Yb atoms to form distorted OCa2Yb3 trigonal bipyramids that share corners with four OCa2Yb3 square pyramids, corners with five OSrYb3 trigonal pyramids, edges with four OCa2Yb3 square pyramids, edges with two equivalent OCa2Yb3 trigonal bipyramids, and edges with three equivalent OCaYb3 trigonal pyramids. In the sixth O site, O is bonded to one Sr and three Yb atoms to form distorted OSrYb3 trigonal pyramids that share corners with six OCa2Yb3 square pyramids, a cornercorner with one OCa2Yb3 trigonal bipyramid, corners with seven OSrYb3 trigonal pyramids, an edgeedge with one OCa2Yb3 square pyramid, and edges with two equivalent OSrYb3 trigonal pyramids.