DOI: 10.17188/1753909
title: Materials Data on La4(ErS2)11 by Materials Project

description: La4(ErS2)11 crystallizes in the monoclinic C2/m 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 ErS6 octahedra, edges with two equivalent ErS6 octahedra, and edges with four equivalent ErS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–50°. There are a spread of Er–S bond distances ranging from 2.69–2.88 Å. In the second Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Er–S bond distances ranging from 2.64–2.77 Å. In the third Er3+ site, Er3+ is bonded to six S2- atoms to form ErS6 octahedra that share corners with three equivalent ErS6 octahedra, corners with two equivalent ErS7 pentagonal bipyramids, and edges with four ErS6 octahedra. The corner-sharing octahedra tilt angles range from 51–63°. There are a spread of Er–S bond distances ranging from 2.65–2.79 Å. In the fourth Er3+ site, Er3+ is bonded to six S2- atoms to form ErS6 octahedra that share corners with three equivalent ErS6 octahedra, a cornercorner with one ErS7 pentagonal bipyramid, edges with four equivalent ErS6 octahedra, and edges with two equivalent ErS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 51–63°. There are a spread of Er–S bond distances ranging from 2.66–2.76 Å. In the fifth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Er–S bond distances ranging from 2.65–2.77 Å. In the sixth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are four shorter (2.72 Å) and two longer (2.73 Å) Er–S bond lengths. There are two inequivalent La+2.75+ sites. In the first La+2.75+ site, La+2.75+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.94–3.07 Å. In the second La+2.75+ site, La+2.75+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.92–3.48 Å. There are eleven inequivalent S2- sites. In the first S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 trigonal bipyramids that share corners with four SLa2Er3 trigonal bipyramids, corners with two SLaEr3 trigonal pyramids, edges with six SLa2Er3 trigonal bipyramids, and edges with two equivalent SEr4 trigonal pyramids. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the third S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and one La+2.75+ atom. In the fourth S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 trigonal bipyramids that share corners with six SLa2Er3 trigonal bipyramids, corners with two equivalent SLaEr3 trigonal pyramids, edges with two equivalent SLa2Er3 square pyramids, edges with four SLa2Er3 trigonal bipyramids, and an edgeedge with one SLaEr3 trigonal pyramid. In the fifth S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 square pyramids that share corners with two equivalent SLa2Er3 square pyramids, corners with four SLa3Er2 trigonal bipyramids, edges with three SLa2Er3 square pyramids, edges with three SLa2Er3 trigonal bipyramids, and edges with two equivalent SLaEr3 trigonal pyramids. In the sixth S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 square pyramids that share corners with four SLa2Er3 square pyramids, corners with two equivalent SLa3Er2 trigonal bipyramids, corners with two equivalent SLaEr3 trigonal pyramids, edges with four SLa2Er3 square pyramids, and edges with three SLa3Er2 trigonal bipyramids. In the seventh S2- site, S2- is bonded to two equivalent Er3+ and three La+2.75+ atoms to form distorted SLa3Er2 trigonal bipyramids that share corners with four SLa2Er3 square pyramids, corners with two equivalent SLa2Er3 trigonal bipyramids, corners with four equivalent SEr4 trigonal pyramids, edges with two SLa2Er3 square pyramids, edges with six SLa2Er3 trigonal bipyramids, and edges with three SLaEr3 trigonal pyramids. In the eighth S2- site, S2- is bonded to three Er3+ and one La+2.75+ atom to form distorted SLaEr3 trigonal pyramids that share corners with two equivalent SLa2Er3 square pyramids, corners with four SLa2Er3 trigonal bipyramids, corners with five SLaEr3 trigonal pyramids, edges with two equivalent SLa2Er3 square pyramids, and edges with three SLa3Er2 trigonal bipyramids. In the ninth S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the tenth S2- site, S2- is bonded to four Er3+ atoms to form distorted SEr4 trigonal pyramids that share corners with five SLa2Er3 trigonal bipyramids, corners with five SLaEr3 trigonal pyramids, edges with three SLa2Er3 trigonal bipyramids, and edges with two equivalent SEr4 trigonal pyramids. In the eleventh S2- site, S2- is bonded to two equivalent Er3+ and three La+2.75+ atoms to form distorted SLa3Er2 trigonal bipyramids that share corners with two equivalent SLa2Er3 square pyramids, corners with four SLa2Er3 trigonal bipyramids, a cornercorner with one SLaEr3 trigonal pyramid, edges with two equivalent SLa2Er3 square pyramids, and edges with six SLa2Er3 trigonal bipyramids.