Materials Data on Lu4CrS7 by Materials Project

Abstract

Lu4CrS7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Lu–S bond distances ranging from 2.68–3.00 Å. In the second Lu3+ site, Lu3+ is bonded to seven S2- atoms to form distorted LuS7 pentagonal bipyramids that share corners with two equivalent CrS6 octahedra, corners with six LuS6 octahedra, edges with four LuS6 octahedra, and faces with two equivalent LuS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 22–67°. There are a spread of Lu–S bond distances ranging from 2.65–2.90 Å. In the third Lu3+ site, Lu3+ is bonded to six S2- atoms to form LuS6 octahedra that share a cornercorner with one LuS6 octahedra, a cornercorner with one CrS6 octahedra, corners with two equivalent LuS7 pentagonal bipyramids, edges with two equivalent LuS6 octahedra, and edges with three equivalent LuS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 51–54°. There are two shorter (2.62 Å) and four longer (2.66 Å) Lu–S bond lengths. In the fourth Lu3+ site, Lu3+ is bonded to six S2- atoms to form LuS6 octahedra that share a cornercorner with one LuS6 octahedra, corners with two equivalent CrS6 octahedra, corners with four equivalent LuS7 pentagonal bipyramids, edges with two equivalent LuS6 octahedra, edges with three equivalent CrS6 octahedra, and an edgeedge with one LuS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 2–51°. There are a spread of Lu–S bond distances ranging from 2.61–2.72 Å. Cr2+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with three LuS6 octahedra, corners with two equivalent LuS7 pentagonal bipyramids, edges with two equivalent CrS6 octahedra, and edges with three equivalent LuS6 octahedra. The corner-sharing octahedra tilt angles range from 2–54°. There are a spread of Cr–S bond distances ranging from 2.45–2.60 Å. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded to four Lu3+ and one Cr2+ atom to form distorted SLu4Cr trigonal bipyramids that share corners with five SLu3Cr tetrahedra, corners with four SLu5 trigonal bipyramids, an edgeedge with one SLu4 tetrahedra, and edges with five SLu4Cr trigonal bipyramids. In the second S2- site, S2- is bonded to three Lu3+ and two equivalent Cr2+ atoms to form distorted SLu3Cr2 trigonal bipyramids that share corners with five SLu3Cr tetrahedra, corners with four SLu5 trigonal bipyramids, an edgeedge with one SLu3Cr tetrahedra, and edges with five SLu4Cr trigonal bipyramids. In the third S2- site, S2- is bonded to five Lu3+ atoms to form distorted SLu5 trigonal bipyramids that share corners with four equivalent SLu3Cr tetrahedra, corners with six SLu4Cr trigonal bipyramids, edges with three SLu3Cr tetrahedra, and edges with six SLu3Cr2 trigonal bipyramids. In the fourth S2- site, S2- is bonded to five Lu3+ atoms to form distorted SLu5 trigonal bipyramids that share corners with four equivalent SLu4 tetrahedra, corners with six SLu4Cr trigonal bipyramids, edges with three SLu3Cr tetrahedra, and edges with six SLu4Cr trigonal bipyramids. In the fifth S2- site, S2- is bonded to three Lu3+ and one Cr2+ atom to form distorted SLu3Cr tetrahedra that share corners with three SLu3Cr tetrahedra, corners with nine SLu4Cr trigonal bipyramids, and edges with four SLu3Cr2 trigonal bipyramids. In the sixth S2- site, S2- is bonded to four Lu3+ atoms to form distorted SLu4 tetrahedra that share corners with three SLu3Cr tetrahedra, corners with nine SLu4Cr trigonal bipyramids, and edges with four SLu4Cr trigonal bipyramids. In the seventh S2- site, S2- is bonded in a rectangular see-saw-like geometry to two equivalent Lu3+ and two equivalent Cr2+ atoms.