DOE OSTI2020
Ho2S3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are six inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to seven S2- atoms to form distorted HoS7 pentagonal bipyramids that share corners with three HoS6 octahedra, corners with two equivalent HoS7 pentagonal bipyramids, edges with two equivalent HoS6 octahedra, edges with six HoS7 pentagonal bipyramids, and a faceface with one HoS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Ho–S bond distances ranging from 2.72–2.95 Å. In the second Ho3+ site, Ho3+ is bonded to six S2- atoms to form HoS6 octahedra that share corners with four HoS6 octahedra, corners with five HoS7 pentagonal bipyramids, edges with four equivalent HoS6 octahedra, and a faceface with one HoS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 63–68°. There are a spread of Ho–S bond distances ranging from 2.68–2.83 Å. In the third Ho3+ site, Ho3+ is bonded to six S2- atoms to form HoS6 octahedra that share corners with four HoS6 octahedra, corners with two HoS7 pentagonal bipyramids, edges with three HoS6 octahedra, and edges with four HoS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 14–63°. There are a spread of Ho–S bond distances ranging from 2.68–2.85 Å. In the fourth Ho3+ site, Ho3+ is bonded to six S2- atoms to form HoS6 octahedra that share corners with four HoS6 octahedra, corners with three HoS7 pentagonal bipyramids, edges with three HoS6 octahedra, and edges with four HoS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 14–68°. There are a spread of Ho–S bond distances ranging from 2.63–2.82 Å. In the fifth Ho3+ site, Ho3+ is bonded to seven S2- atoms to form distorted HoS7 pentagonal bipyramids that share corners with five HoS6 octahedra, edges with four HoS6 octahedra, edges with four equivalent HoS7 pentagonal bipyramids, and a faceface with one HoS6 octahedra. The corner-sharing octahedra tilt angles range from 32–49°. There are a spread of Ho–S bond distances ranging from 2.68–2.93 Å. In the sixth Ho3+ site, Ho3+ is bonded to seven S2- atoms to form distorted HoS7 pentagonal bipyramids that share corners with two HoS6 octahedra, corners with two equivalent HoS7 pentagonal bipyramids, edges with two equivalent HoS6 octahedra, edges with six HoS7 pentagonal bipyramids, and a faceface with one HoS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 33–34°. There are a spread of Ho–S bond distances ranging from 2.72–2.94 Å. There are nine inequivalent S2- sites. In the first S2- site, S2- is bonded to four Ho3+ atoms to form SHo4 trigonal pyramids that share a cornercorner with one SHo5 square pyramid, corners with three equivalent SHo4 tetrahedra, corners with two equivalent SHo5 trigonal bipyramids, corners with two equivalent SHo4 trigonal pyramids, edges with three equivalent SHo5 trigonal bipyramids, and edges with two equivalent SHo4 trigonal pyramids. In the second S2- site, S2- is bonded to four Ho3+ atoms to form distorted SHo4 trigonal pyramids that share corners with two equivalent SHo5 square pyramids, corners with three SHo5 trigonal bipyramids, corners with six SHo4 trigonal pyramids, an edgeedge with one SHo5 square pyramid, edges with two equivalent SHo5 trigonal bipyramids, and edges with two equivalent SHo4 trigonal pyramids. In the third S2- site, S2- is bonded to four Ho3+ atoms to form distorted SHo4 trigonal pyramids that share corners with two equivalent SHo5 square pyramids, corners with five SHo5 trigonal bipyramids, corners with six SHo4 trigonal pyramids, an edgeedge with one SHo5 trigonal bipyramid, and edges with four SHo4 trigonal pyramids. In the fourth S2- site, S2- is bonded to five Ho3+ atoms to form distorted SHo5 trigonal bipyramids that share corners with four equivalent SHo4 tetrahedra, corners with five SHo4 trigonal pyramids, edges with two equivalent SHo5 square pyramids, an edgeedge with one SHo4 tetrahedra, edges with two equivalent SHo5 trigonal bipyramids, and edges with three equivalent SHo4 trigonal pyramids. In the fifth S2- site, S2- is bonded to five Ho3+ atoms to form SHo5 square pyramids that share a cornercorner with one SHo4 tetrahedra, corners with seven SHo4 trigonal pyramids, edges with two equivalent SHo5 square pyramids, edges with two equivalent SHo4 tetrahedra, edges with two equivalent SHo5 trigonal bipyramids, and an edgeedge with one SHo4 trigonal pyramid. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to four Ho3+ atoms. In the seventh S2- site, S2- is bonded to four Ho3+ atoms to form distorted SHo4 tetrahedra that share a cornercorner with one SHo5 square pyramid, corners with two equivalent SHo4 tetrahedra, corners with four equivalent SHo5 trigonal bipyramids, corners with four SHo4 trigonal pyramids, edges with two equivalent SHo5 square pyramids, edges with two equivalent SHo4 tetrahedra, and an edgeedge with one SHo5 trigonal bipyramid. In the eighth S2- site, S2- is bonded to four Ho3+ atoms to form distorted SHo4 trigonal pyramids that share corners with two equivalent SHo5 square pyramids, a cornercorner with one SHo4 tetrahedra, corners with two equivalent SHo5 trigonal bipyramids, corners with eight SHo4 trigonal pyramids, and edges with three equivalent SHo5 trigonal bipyramids. In the ninth S2- site, S2- is bonded to five Ho3+ atoms to form distorted SHo5 trigonal bipyramids that share corners with seven SHo4 trigonal pyramids, edges with four equivalent SHo5 trigonal bipyramids, and edges with six SHo4 trigonal pyramids.