DOI: 10.17188/1263431
title: Materials Data on Er2CdSe4 by Materials Project

description: Er2CdSe4 is Spinel-like structured and crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are eleven inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to four Se2- atoms to form ErSe4 tetrahedra that share corners with three equivalent CdSe6 octahedra and corners with nine ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 58–59°. There are three shorter (2.70 Å) and one longer (2.72 Å) Er–Se bond lengths. In the second Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with three ErSe4 tetrahedra, corners with three CdSe4 tetrahedra, edges with two CdSe6 octahedra, and edges with four equivalent ErSe6 octahedra. There are a spread of Er–Se bond distances ranging from 2.83–2.88 Å. In the third Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share a cornercorner with one ErSe4 tetrahedra, corners with five CdSe4 tetrahedra, an edgeedge with one CdSe6 octahedra, and edges with five ErSe6 octahedra. There are a spread of Er–Se bond distances ranging from 2.83–2.88 Å. In the fourth Er3+ site, Er3+ is bonded to four Se2- atoms to form ErSe4 tetrahedra that share corners with three equivalent CdSe6 octahedra and corners with nine ErSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are three shorter (2.70 Å) and one longer (2.73 Å) Er–Se bond lengths. In the fifth Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with six CdSe4 tetrahedra and edges with six ErSe6 octahedra. All Er–Se bond lengths are 2.85 Å. In the sixth Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with six CdSe4 tetrahedra and edges with six ErSe6 octahedra. There are three shorter (2.84 Å) and three longer (2.86 Å) Er–Se bond lengths. In the seventh Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with six CdSe4 tetrahedra and edges with six ErSe6 octahedra. All Er–Se bond lengths are 2.85 Å. In the eighth Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with six CdSe4 tetrahedra and edges with six ErSe6 octahedra. All Er–Se bond lengths are 2.85 Å. In the ninth Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with six CdSe4 tetrahedra and edges with six ErSe6 octahedra. All Er–Se bond lengths are 2.85 Å. In the tenth Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with two equivalent ErSe4 tetrahedra, corners with four CdSe4 tetrahedra, an edgeedge with one CdSe6 octahedra, and edges with five ErSe6 octahedra. There are two shorter (2.84 Å) and four longer (2.85 Å) Er–Se bond lengths. In the eleventh Er3+ site, Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with six CdSe4 tetrahedra and edges with six ErSe6 octahedra. There are three shorter (2.84 Å) and three longer (2.86 Å) Er–Se bond lengths. There are eleven inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with three equivalent CdSe6 octahedra and corners with nine ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 55–57°. There are three shorter (2.68 Å) and one longer (2.74 Å) Cd–Se bond lengths. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with three equivalent CdSe6 octahedra and corners with nine ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 55–57°. There are three shorter (2.68 Å) and one longer (2.74 Å) Cd–Se bond lengths. In the third Cd2+ site, Cd2+ is bonded to six Se2- atoms to form CdSe6 octahedra that share corners with three equivalent ErSe4 tetrahedra, corners with three equivalent CdSe4 tetrahedra, and edges with six ErSe6 octahedra. There are three shorter (2.82 Å) and three longer (2.91 Å) Cd–Se bond lengths. In the fourth Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are one shorter (2.69 Å) and three longer (2.70 Å) Cd–Se bond lengths. In the fifth Cd2+ site, Cd2+ is bonded to six Se2- atoms to form CdSe6 octahedra that share corners with three equivalent ErSe4 tetrahedra, corners with three equivalent CdSe4 tetrahedra, and edges with six ErSe6 octahedra. There are three shorter (2.83 Å) and three longer (2.90 Å) Cd–Se bond lengths. In the sixth Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Cd–Se bond lengths are 2.70 Å. In the seventh Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Cd–Se bond lengths are 2.70 Å. In the eighth Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. All Cd–Se bond lengths are 2.70 Å. In the ninth Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. All Cd–Se bond lengths are 2.70 Å. In the tenth Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are one shorter (2.69 Å) and three longer (2.70 Å) Cd–Se bond lengths. In the eleventh Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with twelve ErSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are one shorter (2.69 Å) and three longer (2.70 Å) Cd–Se bond lengths. There are twenty-four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Er3+ and two Cd2+ atoms. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the third Se2- site, Se2- is bonded to three Er3+ and one Cd2+ atom to form a mixture of distorted corner and edge-sharing SeEr3Cd trigonal pyramids. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Er3+ and two Cd2+ atoms. In the fifth Se2- site, Se2- is bonded to four Er3+ atoms to form a mixture of distorted corner and edge-sharing SeEr4 trigonal pyramids. In the sixth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the seventh Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. In the eighth Se2- site, Se2- is bonded to three Er3+ and one Cd2+ atom to form a mixture of distorted corner and edge-sharing SeEr3Cd trigonal pyramids. In the ninth Se2- site, Se2- is bonded to four Er3+ atoms to form a mixture of distorted corner and edge-sharing SeEr4 trigonal pyramids. In the tenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the eleventh Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. In the twelfth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. In the thirteenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the fourteenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the fifteenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. The Se–Er bond length is 2.85 Å. The Se–Cd bond length is 2.70 Å. In the sixteenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. The Se–Er bond length is 2.85 Å. In the seventeenth Se2- site, Se2- is bonded in a distorted trigonal pyramidal geometry to three equivalent Er3+ and one Cd2+ atom. In the eighteenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the nineteenth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. In the twentieth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cd2+ atom. In the twenty-first Se2- site, Se2- is bonded in a distorted trigonal pyramidal geometry to three equivalent Er3+ and one Cd2+ atom. The Se–Cd bond length is 2.70 Å. In the twenty-second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Cd2+ atom. In the twenty-third Se2- site, Se2- is bonded to three Er3+ and one Cd2+ atom to form distorted SeEr3Cd trigonal pyramids that share corners with three SeEr4 trigonal pyramids and edges with three SeEr3Cd trigonal pyramids. In the twenty-fourth Se2- site, Se2- is bonded to three equivalent Er3+ and one Cd2+ atom to form distorted edge-sharing SeEr3Cd trigonal pyramids.