Materials Data on Ho4FeSe7 by Materials Project

Abstract

Ho4FeSe7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Ho–Se bond distances ranging from 2.85–3.27 Å. In the second Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Ho–Se bond distances ranging from 2.82–3.12 Å. In the third Ho3+ site, Ho3+ is bonded to six Se2- atoms to form HoSe6 octahedra that share a cornercorner with one HoSe6 octahedra, a cornercorner with one FeSe6 octahedra, and edges with two equivalent HoSe6 octahedra. The corner-sharing octahedra tilt angles range from 45–51°. There are a spread of Ho–Se bond distances ranging from 2.78–2.81 Å. In the fourth Ho3+ site, Ho3+ is bonded to six Se2- atoms to form HoSe6 octahedra that share a cornercorner with one HoSe6 octahedra, corners with two equivalent FeSe6 octahedra, edges with two equivalent HoSe6 octahedra, and edges with three equivalent FeSe6 octahedra. The corner-sharing octahedra tilt angles range from 8–45°. There are a spread of Ho–Se bond distances ranging from 2.78–2.91 Å. Fe2+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with three HoSe6 octahedra, edges with two equivalent FeSe6 octahedra, and edges with three equivalent HoSe6 octahedra. The corner-sharing octahedra tilt angles range from 8–51°. There are a spread of Fe–Se bond distances ranging from 2.45–2.61 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Ho3+ and one Fe2+ atom to form distorted SeHo4Fe trigonal bipyramids that share corners with four equivalent SeHo4 tetrahedra, edges with two equivalent SeHo3Fe2 square pyramids, an edgeedge with one SeHo4 tetrahedra, and edges with two equivalent SeHo4Fe trigonal bipyramids. In the second Se2- site, Se2- is bonded to three Ho3+ and two equivalent Fe2+ atoms to form SeHo3Fe2 square pyramids that share a cornercorner with one SeHo4 tetrahedra, edges with two equivalent SeHo3Fe2 square pyramids, and edges with two equivalent SeHo4Fe trigonal bipyramids. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to five Ho3+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to five Ho3+ atoms. In the fifth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Ho3+ and one Fe2+ atom. In the sixth Se2- site, Se2- is bonded to four Ho3+ atoms to form distorted SeHo4 tetrahedra that share a cornercorner with one SeHo3Fe2 square pyramid, corners with two equivalent SeHo4 tetrahedra, corners with four equivalent SeHo4Fe trigonal bipyramids, and an edgeedge with one SeHo4Fe trigonal bipyramid. In the seventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two equivalent Ho3+ and two equivalent Fe2+ atoms.