Materials Data on Ba5Eu8Zn4O21 by Materials Project

Abstract

Ba5Eu8Zn4O21 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are two 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 2.69–3.26 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are two shorter (2.92 Å) and eight longer (2.99 Å) Ba–O bond lengths. There are two inequivalent Eu3+ sites. In the first Eu3+ site, Eu3+ is bonded to seven O2- atoms to form distorted EuO7 pentagonal bipyramids that share corners with three EuO7 pentagonal bipyramids, corners with two equivalent ZnO5 trigonal bipyramids, edges with three equivalent EuO7 pentagonal bipyramids, edges with two equivalent ZnO5 trigonal bipyramids, and faces with two equivalent EuO7 pentagonal bipyramids. There are a spread of Eu–O bond distances ranging from 2.38–2.47 Å. In the second Eu3+ site, Eu3+ is bonded to seven O2- atoms to form distorted EuO7 pentagonal bipyramids that share corners with two equivalent EuO7 pentagonal bipyramids, corners with two equivalent ZnO5 trigonal bipyramids, edges with five EuO7 pentagonal bipyramids, an edgeedge with one ZnO5 trigonal bipyramid, and a faceface with one ZnO5 trigonal bipyramid. There are a spread of Eu–O bond distances ranging from 2.34–2.60 Å. Zn2+ is bonded to five O2- atoms to form distorted ZnO5 trigonal bipyramids that share corners with four EuO7 pentagonal bipyramids, edges with three EuO7 pentagonal bipyramids, and a faceface with one EuO7 pentagonal bipyramid. There are a spread of Zn–O bond distances ranging from 2.02–2.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, three Eu3+, and one Zn2+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, three Eu3+, and one Zn2+ atom. In the third O2- site, O2- is bonded to four equivalent Ba2+, one Eu3+, and one Zn2+ atom to form a mixture of distorted edge and corner-sharing OBa4EuZn octahedra. The corner-sharing octahedral tilt angles are 7°. In the fourth O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent Eu3+ atoms to form distorted corner-sharing OBa2Eu4 octahedra. The corner-sharing octahedral tilt angles are 0°.