DOI: 10.17188/1730189
title: Materials Data on Er9B5S21 by Materials Project

description: Er9B5S21 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are six inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share corners with three ErS7 pentagonal bipyramids, corners with two BS4 tetrahedra, and an edgeedge with one BS4 tetrahedra. There are a spread of Er–S bond distances ranging from 2.69–2.88 Å. In the second Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Er–S bond distances ranging from 2.69–3.04 Å. In the third Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Er–S bond distances ranging from 2.62–2.87 Å. In the fourth Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Er–S bond distances ranging from 2.68–3.03 Å. In the fifth Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Er–S bond distances ranging from 2.64–2.88 Å. In the sixth Er3+ site, Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share corners with three ErS7 pentagonal bipyramids, corners with two BS4 tetrahedra, and an edgeedge with one BS4 tetrahedra. There are a spread of Er–S bond distances ranging from 2.72–2.88 Å. There are six inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four S2- atoms to form BS4 tetrahedra that share corners with two ErS7 pentagonal bipyramids and an edgeedge with one ErS7 pentagonal bipyramid. There is two shorter (1.93 Å) and two longer (1.97 Å) B–S bond length. In the second B3+ site, B3+ is bonded to four S2- atoms to form BS4 tetrahedra that share corners with two ErS7 pentagonal bipyramids and an edgeedge with one ErS7 pentagonal bipyramid. There are a spread of B–S bond distances ranging from 1.93–1.96 Å. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All B–S bond lengths are 1.83 Å. In the fourth B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All B–S bond lengths are 1.83 Å. In the fifth B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All B–S bond lengths are 1.83 Å. In the sixth B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All B–S bond lengths are 1.83 Å. There are fourteen inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one B3+ atom. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one B3+ atom. In the third S2- site, S2- is bonded to four Er3+ atoms to form distorted corner-sharing SEr4 trigonal pyramids. In the fourth S2- site, S2- is bonded in a distorted see-saw-like geometry to three Er3+ and one B3+ atom. In the fifth S2- site, S2- is bonded in a 1-coordinate geometry to three Er3+ and one B3+ atom. In the sixth S2- site, S2- is bonded to four Er3+ atoms to form distorted SEr4 trigonal pyramids that share corners with three SEr4 trigonal pyramids and an edgeedge with one SEr3B trigonal pyramid. In the seventh S2- site, S2- is bonded in a distorted see-saw-like geometry to three Er3+ and one B3+ atom. In the eighth S2- site, S2- is bonded in a 1-coordinate geometry to three Er3+ and one B3+ atom. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one B3+ atom. In the tenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one B3+ atom. In the eleventh S2- site, S2- is bonded to three Er3+ and one B3+ atom to form a mixture of distorted edge and corner-sharing SEr3B trigonal pyramids. In the twelfth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one B3+ atom. In the thirteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one B3+ atom. In the fourteenth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one B3+ atom.