DOI: 10.17188/1732406
title: Materials Data on Ho4CdSe7 by Materials Project

description: Ho4CdSe7 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 to seven Se2- atoms to form distorted HoSe7 pentagonal bipyramids that share corners with four HoSe6 octahedra, corners with four equivalent CdSe6 octahedra, an edgeedge with one CdSe6 octahedra, edges with three equivalent HoSe6 octahedra, edges with two equivalent HoSe7 pentagonal bipyramids, and faces with two equivalent HoSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 22–69°. There are a spread of Ho–Se bond distances ranging from 2.84–3.18 Å. In the second Ho3+ site, Ho3+ is bonded to seven Se2- atoms to form distorted HoSe7 pentagonal bipyramids that share corners with two equivalent CdSe6 octahedra, corners with six HoSe6 octahedra, edges with four HoSe6 octahedra, edges with two equivalent HoSe7 pentagonal bipyramids, and faces with two equivalent HoSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 21–68°. There are a spread of Ho–Se bond distances ranging from 2.84–3.11 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 CdSe6 octahedra, corners with four HoSe7 pentagonal bipyramids, edges with two equivalent HoSe6 octahedra, and edges with six HoSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 54–56°. There are a spread of Ho–Se bond distances ranging from 2.79–2.87 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 CdSe6 octahedra, corners with six HoSe7 pentagonal bipyramids, edges with two equivalent HoSe6 octahedra, edges with three equivalent CdSe6 octahedra, and an edgeedge with one HoSe7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 3–54°. There are a spread of Ho–Se bond distances ranging from 2.77–2.91 Å. Cd2+ is bonded to six Se2- atoms to form CdSe6 octahedra that share corners with three HoSe6 octahedra, corners with six HoSe7 pentagonal bipyramids, edges with two equivalent CdSe6 octahedra, edges with three equivalent HoSe6 octahedra, and an edgeedge with one HoSe7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 3–56°. There are a spread of Cd–Se bond distances ranging from 2.77–2.89 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Ho3+ and one Cd2+ atom to form distorted SeHo4Cd trigonal bipyramids that share corners with five SeHo3Cd tetrahedra, corners with four SeHo5 trigonal bipyramids, an edgeedge with one SeHo4 tetrahedra, and edges with five SeHo4Cd trigonal bipyramids. In the second Se2- site, Se2- is bonded to three Ho3+ and two equivalent Cd2+ atoms to form distorted SeHo3Cd2 trigonal bipyramids that share corners with five SeHo3Cd tetrahedra, corners with four SeHo5 trigonal bipyramids, an edgeedge with one SeHo3Cd tetrahedra, and edges with five SeHo4Cd trigonal bipyramids. In the third Se2- site, Se2- is bonded to five Ho3+ atoms to form distorted SeHo5 trigonal bipyramids that share corners with four equivalent SeHo3Cd tetrahedra, corners with six SeHo4Cd trigonal bipyramids, edges with three SeHo3Cd tetrahedra, and edges with six SeHo3Cd2 trigonal bipyramids. In the fourth Se2- site, Se2- is bonded to five Ho3+ atoms to form distorted SeHo5 trigonal bipyramids that share corners with four equivalent SeHo4 tetrahedra, corners with six SeHo4Cd trigonal bipyramids, edges with three SeHo3Cd tetrahedra, and edges with six SeHo4Cd trigonal bipyramids. In the fifth Se2- site, Se2- is bonded to three Ho3+ and one Cd2+ atom to form distorted SeHo3Cd tetrahedra that share corners with three SeHo3Cd tetrahedra, corners with nine SeHo4Cd trigonal bipyramids, and edges with four SeHo3Cd2 trigonal bipyramids. In the sixth Se2- site, Se2- is bonded to four Ho3+ atoms to form distorted SeHo4 tetrahedra that share corners with three SeHo3Cd tetrahedra, corners with nine SeHo4Cd trigonal bipyramids, and edges with four SeHo4Cd trigonal bipyramids. In the seventh Se2- site, Se2- is bonded in a square co-planar geometry to two equivalent Ho3+ and two equivalent Cd2+ atoms.