Cr8Cu3ZnSe16 is Spinel-derived structured and crystallizes in the trigonal R3m space group. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent Se(3) and three equivalent Se(7) atoms to form CrSe6 octahedra that share corners with three equivalent Cu(2)Se4 tetrahedra, corners with three equivalent Zn(1)Se4 tetrahedra, edges with three equivalent Cr(3)Se6 octahedra, and edges with three equivalent Cr(4)Se6 octahedra. In the second Cr site, Cr(2) is bonded to three equivalent Se(4) and three equivalent Se(8) atoms to form CrSe6 octahedra that share corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent Cu(3)Se4 tetrahedra, edges with three equivalent Cr(3)Se6 octahedra, and edges with three equivalent Cr(4)Se6 octahedra. In the third Cr site, Cr(3) is bonded to one Se(2), one Se(5), two equivalent Se(3), and two equivalent Se(8) atoms to form CrSe6 octahedra that share  a cornercorner with one Cu(1)Se4 tetrahedra,  a cornercorner with one Cu(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra,  an edgeedge with one Cr(1)Se6 octahedra,  an edgeedge with one Cr(2)Se6 octahedra, and edges with four equivalent Cr(3)Se6 octahedra. In the fourth Cr site, Cr(4) is bonded to one Se(1), one Se(6), two equivalent Se(4), and two equivalent Se(7) atoms to form CrSe6 octahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one Zn(1)Se4 tetrahedra, corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra,  an edgeedge with one Cr(1)Se6 octahedra,  an edgeedge with one Cr(2)Se6 octahedra, and edges with four equivalent Cr(4)Se6 octahedra. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(2) and three equivalent Se(4) atoms to form CuSe4 tetrahedra that share corners with three equivalent Cr(2)Se6 octahedra, corners with three equivalent Cr(3)Se6 octahedra, and corners with six equivalent Cr(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the second Cu site, Cu(2) is bonded to one Se(5) and three equivalent Se(7) atoms to form CuSe4 tetrahedra that share corners with three equivalent Cr(1)Se6 octahedra, corners with three equivalent Cr(3)Se6 octahedra, and corners with six equivalent Cr(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. In the third Cu site, Cu(3) is bonded to one Se(6) and three equivalent Se(8) atoms to form CuSe4 tetrahedra that share corners with three equivalent Cr(2)Se6 octahedra, corners with three equivalent Cr(4)Se6 octahedra, and corners with six equivalent Cr(3)Se6 octahedra. The corner-sharing octahedral tilt angles are 57°. Zn(1) is bonded to one Se(1) and three equivalent Se(3) atoms to form ZnSe4 tetrahedra that share corners with three equivalent Cr(1)Se6 octahedra, corners with three equivalent Cr(4)Se6 octahedra, and corners with six equivalent Cr(3)Se6 octahedra. The corner-sharing octahedral tilt angles range from 58-59°. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Cr(4) and one Zn(1) atom to form distorted SeZnCr3 trigonal pyramids that share corners with three equivalent Se(6)Cr3Cu trigonal pyramids and corners with three equivalent Se(3)ZnCr3 trigonal pyramids. In the second Se site, Se(2) is bonded to three equivalent Cr(3) and one Cu(1) atom to form distorted edge-sharing SeCr3Cu trigonal pyramids. In the third Se site, Se(3) is bonded to one Cr(1), two equivalent Cr(3), and one Zn(1) atom to form distorted SeZnCr3 trigonal pyramids that share  a cornercorner with one Se(1)ZnCr3 trigonal pyramid, corners with two equivalent Se(3)ZnCr3 trigonal pyramids,  an edgeedge with one Se(2)Cr3Cu trigonal pyramid, and edges with two equivalent Se(3)ZnCr3 trigonal pyramids. In the fourth Se site, Se(4) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(4), and one Cu(1) atom. In the fifth Se site, Se(5) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(3) and one Cu(2) atom. In the sixth Se site, Se(6) is bonded to three equivalent Cr(4) and one Cu(3) atom to form distorted corner-sharing SeCr3Cu trigonal pyramids. In the seventh Se site, Se(7) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(4), and one Cu(2) atom. In the eighth Se site, Se(8) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(3), and one Cu(3) atom.
Cr8Cu3ZnSe16 is Spinel-derived structured and crystallizes in the trigonal R3m space group. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent Se(3) and three equivalent Se(7) atoms to form CrSe6 octahedra that share corners with three equivalent Cu(2)Se4 tetrahedra, corners with three equivalent Zn(1)Se4 tetrahedra, edges with three equivalent Cr(3)Se6 octahedra, and edges with three equivalent Cr(4)Se6 octahedra. All Cr(1)-Se(3) bond lengths are 2.54 Å. All Cr(1)-Se(7) bond lengths are 2.51 Å. In the second Cr site, Cr(2) is bonded to three equivalent Se(4) and three equivalent Se(8) atoms to form CrSe6 octahedra that share corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent Cu(3)Se4 tetrahedra, edges with three equivalent Cr(3)Se6 octahedra, and edges with three equivalent Cr(4)Se6 octahedra. All Cr(2)-Se(4) bond lengths are 2.53 Å. All Cr(2)-Se(8) bond lengths are 2.53 Å. In the third Cr site, Cr(3) is bonded to one Se(2), one Se(5), two equivalent Se(3), and two equivalent Se(8) atoms to form CrSe6 octahedra that share  a cornercorner with one Cu(1)Se4 tetrahedra,  a cornercorner with one Cu(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra,  an edgeedge with one Cr(1)Se6 octahedra,  an edgeedge with one Cr(2)Se6 octahedra, and edges with four equivalent Cr(3)Se6 octahedra. The Cr(3)-Se(2) bond length is 2.53 Å. The Cr(3)-Se(5) bond length is 2.52 Å. Both Cr(3)-Se(3) bond lengths are 2.53 Å. Both Cr(3)-Se(8) bond lengths are 2.51 Å. In the fourth Cr site, Cr(4) is bonded to one Se(1), one Se(6), two equivalent Se(4), and two equivalent Se(7) atoms to form CrSe6 octahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one Zn(1)Se4 tetrahedra, corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra,  an edgeedge with one Cr(1)Se6 octahedra,  an edgeedge with one Cr(2)Se6 octahedra, and edges with four equivalent Cr(4)Se6 octahedra. The Cr(4)-Se(1) bond length is 2.52 Å. The Cr(4)-Se(6) bond length is 2.51 Å. Both Cr(4)-Se(4) bond lengths are 2.53 Å. Both Cr(4)-Se(7) bond lengths are 2.53 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(2) and three equivalent Se(4) atoms to form CuSe4 tetrahedra that share corners with three equivalent Cr(2)Se6 octahedra, corners with three equivalent Cr(3)Se6 octahedra, and corners with six equivalent Cr(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Cu(1)-Se(2) bond length is 2.40 Å. All Cu(1)-Se(4) bond lengths are 2.40 Å. In the second Cu site, Cu(2) is bonded to one Se(5) and three equivalent Se(7) atoms to form CuSe4 tetrahedra that share corners with three equivalent Cr(1)Se6 octahedra, corners with three equivalent Cr(3)Se6 octahedra, and corners with six equivalent Cr(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 56-57°. The Cu(2)-Se(5) bond length is 2.40 Å. All Cu(2)-Se(7) bond lengths are 2.40 Å. In the third Cu site, Cu(3) is bonded to one Se(6) and three equivalent Se(8) atoms to form CuSe4 tetrahedra that share corners with three equivalent Cr(2)Se6 octahedra, corners with three equivalent Cr(4)Se6 octahedra, and corners with six equivalent Cr(3)Se6 octahedra. The corner-sharing octahedral tilt angles are 57°. The Cu(3)-Se(6) bond length is 2.39 Å. All Cu(3)-Se(8) bond lengths are 2.40 Å. Zn(1) is bonded to one Se(1) and three equivalent Se(3) atoms to form ZnSe4 tetrahedra that share corners with three equivalent Cr(1)Se6 octahedra, corners with three equivalent Cr(4)Se6 octahedra, and corners with six equivalent Cr(3)Se6 octahedra. The corner-sharing octahedral tilt angles range from 58-59°. The Zn(1)-Se(1) bond length is 2.45 Å. All Zn(1)-Se(3) bond lengths are 2.45 Å. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Cr(4) and one Zn(1) atom to form distorted SeZnCr3 trigonal pyramids that share corners with three equivalent Se(6)Cr3Cu trigonal pyramids and corners with three equivalent Se(3)ZnCr3 trigonal pyramids. In the second Se site, Se(2) is bonded to three equivalent Cr(3) and one Cu(1) atom to form distorted edge-sharing SeCr3Cu trigonal pyramids. In the third Se site, Se(3) is bonded to one Cr(1), two equivalent Cr(3), and one Zn(1) atom to form distorted SeZnCr3 trigonal pyramids that share  a cornercorner with one Se(1)ZnCr3 trigonal pyramid, corners with two equivalent Se(3)ZnCr3 trigonal pyramids,  an edgeedge with one Se(2)Cr3Cu trigonal pyramid, and edges with two equivalent Se(3)ZnCr3 trigonal pyramids. In the fourth Se site, Se(4) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(4), and one Cu(1) atom. In the fifth Se site, Se(5) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(3) and one Cu(2) atom. In the sixth Se site, Se(6) is bonded to three equivalent Cr(4) and one Cu(3) atom to form distorted corner-sharing SeCr3Cu trigonal pyramids. In the seventh Se site, Se(7) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(4), and one Cu(2) atom. In the eighth Se site, Se(8) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(3), and one Cu(3) atom.