DOI: 10.17188/1652117
title: Materials Data on Zn3Cr8FeSe16 by Materials Project

description: Cr8FeZn3Se16 is Spinel-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with three equivalent FeSe4 tetrahedra, corners with three equivalent ZnSe4 tetrahedra, and edges with six CrSe6 octahedra. There are three shorter (2.54 Å) and three longer (2.56 Å) Cr–Se bond lengths. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six ZnSe4 tetrahedra and edges with six CrSe6 octahedra. All Cr–Se bond lengths are 2.54 Å. In the third Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent FeSe4 tetrahedra, corners with four ZnSe4 tetrahedra, and edges with six CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.53–2.56 Å. In the fourth Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share a cornercorner with one FeSe4 tetrahedra, corners with five ZnSe4 tetrahedra, and edges with six CrSe6 octahedra. There are five shorter (2.54 Å) and one longer (2.56 Å) Cr–Se bond lengths. Fe2+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are one shorter (2.44 Å) and three longer (2.45 Å) Fe–Se bond lengths. There are three inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four Se2- atoms to form ZnSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are three shorter (2.48 Å) and one longer (2.49 Å) Zn–Se bond lengths. In the second Zn2+ site, Zn2+ is bonded to four Se2- atoms to form ZnSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Zn–Se bond lengths are 2.48 Å. In the third Zn2+ site, Zn2+ is bonded to four Se2- atoms to form ZnSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Zn–Se bond lengths are 2.48 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeZnCr3 trigonal pyramids and edges with three equivalent SeCr3Fe trigonal pyramids. In the second Se2- site, Se2- is bonded to three equivalent Cr3+ and one Fe2+ atom to form a mixture of distorted corner and edge-sharing SeCr3Fe trigonal pyramids. In the third Se2- site, Se2- is bonded to three Cr3+ and one Fe2+ atom to form distorted SeCr3Fe trigonal pyramids that share corners with twelve SeCr3Fe trigonal pyramids and edges with three SeZnCr3 trigonal pyramids. In the fourth Se2- site, Se2- is bonded to three Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeZnCr3 trigonal pyramids and edges with three SeCr3Fe trigonal pyramids. In the fifth Se2- site, Se2- is bonded to three equivalent Cr3+ and one Zn2+ atom to form a mixture of distorted corner and edge-sharing SeZnCr3 trigonal pyramids. In the sixth Se2- site, Se2- is bonded to three equivalent Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeCr3Fe trigonal pyramids and edges with three equivalent SeZnCr3 trigonal pyramids. In the seventh Se2- site, Se2- is bonded to three Cr3+ and one Zn2+ atom to form a mixture of distorted corner and edge-sharing SeZnCr3 trigonal pyramids. In the eighth Se2- site, Se2- is bonded to three Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeCr3Fe trigonal pyramids and edges with three SeZnCr3 trigonal pyramids.