DOI: 10.17188/1758475
title: Materials Data on Dy4CdSe7 by Materials Project

description: Dy4CdSe7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded to seven Se2- atoms to form distorted DySe7 pentagonal bipyramids that share corners with four DySe6 octahedra, corners with four equivalent CdSe6 octahedra, an edgeedge with one CdSe6 octahedra, edges with three equivalent DySe6 octahedra, edges with two equivalent DySe7 pentagonal bipyramids, and faces with two equivalent DySe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 22–70°. There are a spread of Dy–Se bond distances ranging from 2.85–3.19 Å. In the second Dy3+ site, Dy3+ is bonded to seven Se2- atoms to form distorted DySe7 pentagonal bipyramids that share corners with two equivalent CdSe6 octahedra, corners with six DySe6 octahedra, edges with four DySe6 octahedra, edges with two equivalent DySe7 pentagonal bipyramids, and faces with two equivalent DySe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 22–68°. There are a spread of Dy–Se bond distances ranging from 2.84–3.13 Å. In the third Dy3+ site, Dy3+ is bonded to six Se2- atoms to form DySe6 octahedra that share a cornercorner with one DySe6 octahedra, a cornercorner with one CdSe6 octahedra, corners with four DySe7 pentagonal bipyramids, edges with two equivalent DySe6 octahedra, and edges with six DySe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 54–55°. There are a spread of Dy–Se bond distances ranging from 2.80–2.88 Å. In the fourth Dy3+ site, Dy3+ is bonded to six Se2- atoms to form DySe6 octahedra that share a cornercorner with one DySe6 octahedra, corners with two equivalent CdSe6 octahedra, corners with six DySe7 pentagonal bipyramids, edges with two equivalent DySe6 octahedra, edges with three equivalent CdSe6 octahedra, and an edgeedge with one DySe7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 2–54°. There are a spread of Dy–Se bond distances ranging from 2.78–2.92 Å. Cd2+ is bonded to six Se2- atoms to form CdSe6 octahedra that share corners with three DySe6 octahedra, corners with six DySe7 pentagonal bipyramids, edges with two equivalent CdSe6 octahedra, edges with three equivalent DySe6 octahedra, and an edgeedge with one DySe7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 2–55°. There are a spread of Cd–Se bond distances ranging from 2.77–2.90 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Dy3+ and one Cd2+ atom to form distorted SeDy4Cd trigonal bipyramids that share corners with five SeDy3Cd tetrahedra, corners with four SeDy5 trigonal bipyramids, an edgeedge with one SeDy4 tetrahedra, and edges with five SeDy4Cd trigonal bipyramids. In the second Se2- site, Se2- is bonded to three Dy3+ and two equivalent Cd2+ atoms to form distorted SeDy3Cd2 trigonal bipyramids that share corners with five SeDy3Cd tetrahedra, corners with four SeDy5 trigonal bipyramids, an edgeedge with one SeDy3Cd tetrahedra, and edges with five SeDy4Cd trigonal bipyramids. In the third Se2- site, Se2- is bonded to five Dy3+ atoms to form distorted SeDy5 trigonal bipyramids that share corners with four equivalent SeDy3Cd tetrahedra, corners with six SeDy4Cd trigonal bipyramids, edges with three SeDy3Cd tetrahedra, and edges with six SeDy3Cd2 trigonal bipyramids. In the fourth Se2- site, Se2- is bonded to five Dy3+ atoms to form distorted SeDy5 trigonal bipyramids that share corners with four equivalent SeDy4 tetrahedra, corners with six SeDy4Cd trigonal bipyramids, edges with three SeDy3Cd tetrahedra, and edges with six SeDy4Cd trigonal bipyramids. In the fifth Se2- site, Se2- is bonded to three Dy3+ and one Cd2+ atom to form distorted SeDy3Cd tetrahedra that share corners with three SeDy3Cd tetrahedra, corners with nine SeDy4Cd trigonal bipyramids, and edges with four SeDy3Cd2 trigonal bipyramids. In the sixth Se2- site, Se2- is bonded to four Dy3+ atoms to form distorted SeDy4 tetrahedra that share corners with three SeDy3Cd tetrahedra, corners with nine SeDy4Cd trigonal bipyramids, and edges with four SeDy4Cd trigonal bipyramids. In the seventh Se2- site, Se2- is bonded in a square co-planar geometry to two equivalent Dy3+ and two equivalent Cd2+ atoms.