DOI: 10.17188/1721211
title: Materials Data on Tm4CrS7 by Materials Project

description: Tm4CrS7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Tm–S bond distances ranging from 2.71–3.05 Å. In the second Tm3+ site, Tm3+ is bonded to seven S2- atoms to form distorted TmS7 pentagonal bipyramids that share corners with two equivalent CrS6 octahedra, corners with six TmS6 octahedra, edges with four TmS6 octahedra, and faces with two equivalent TmS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 21–68°. There are a spread of Tm–S bond distances ranging from 2.67–2.93 Å. In the third Tm3+ site, Tm3+ is bonded to six S2- atoms to form TmS6 octahedra that share a cornercorner with one TmS6 octahedra, a cornercorner with one CrS6 octahedra, corners with two equivalent TmS7 pentagonal bipyramids, edges with two equivalent TmS6 octahedra, and edges with three equivalent TmS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Tm–S bond distances ranging from 2.65–2.69 Å. In the fourth Tm3+ site, Tm3+ is bonded to six S2- atoms to form TmS6 octahedra that share a cornercorner with one TmS6 octahedra, corners with two equivalent CrS6 octahedra, corners with four equivalent TmS7 pentagonal bipyramids, edges with two equivalent TmS6 octahedra, edges with three equivalent CrS6 octahedra, and an edgeedge with one TmS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 3–50°. There are a spread of Tm–S bond distances ranging from 2.64–2.76 Å. Cr2+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with three TmS6 octahedra, corners with two equivalent TmS7 pentagonal bipyramids, edges with two equivalent CrS6 octahedra, and edges with three equivalent TmS6 octahedra. The corner-sharing octahedra tilt angles range from 3–54°. There are a spread of Cr–S bond distances ranging from 2.44–2.60 Å. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded to four Tm3+ and one Cr2+ atom to form distorted STm4Cr trigonal bipyramids that share corners with five STm3Cr tetrahedra, corners with two equivalent STm5 trigonal bipyramids, edges with two equivalent STm3Cr2 square pyramids, an edgeedge with one STm4 tetrahedra, and edges with two equivalent STm4Cr trigonal bipyramids. In the second S2- site, S2- is bonded to three Tm3+ and two equivalent Cr2+ atoms to form distorted STm3Cr2 square pyramids that share corners with five STm3Cr tetrahedra, corners with two equivalent STm5 trigonal bipyramids, edges with two equivalent STm3Cr2 square pyramids, an edgeedge with one STm3Cr tetrahedra, and edges with three STm4Cr trigonal bipyramids. In the third S2- site, S2- is bonded to five Tm3+ atoms to form distorted STm5 trigonal bipyramids that share corners with two equivalent STm3Cr2 square pyramids, corners with four equivalent STm3Cr tetrahedra, corners with two equivalent STm4Cr trigonal bipyramids, an edgeedge with one STm3Cr2 square pyramid, edges with three STm3Cr tetrahedra, and edges with two equivalent STm5 trigonal bipyramids. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to five Tm3+ atoms. In the fifth S2- site, S2- is bonded to three Tm3+ and one Cr2+ atom to form distorted STm3Cr tetrahedra that share corners with four equivalent STm3Cr2 square pyramids, corners with three STm3Cr tetrahedra, corners with five STm4Cr trigonal bipyramids, an edgeedge with one STm3Cr2 square pyramid, and an edgeedge with one STm5 trigonal bipyramid. In the sixth S2- site, S2- is bonded to four Tm3+ atoms to form distorted STm4 tetrahedra that share a cornercorner with one STm3Cr2 square pyramid, corners with three STm3Cr tetrahedra, corners with four equivalent STm4Cr trigonal bipyramids, and edges with three STm4Cr trigonal bipyramids. In the seventh S2- site, S2- is bonded in a rectangular see-saw-like geometry to two equivalent Tm3+ and two equivalent Cr2+ atoms.