Cs3Cu20Te13 crystallizes in the cubic Fm-3 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to four equivalent Cu(1), twelve equivalent Cu(2), and twelve equivalent Te(1) atoms to form distorted CsCu16Te12 tetrahedra that share faces with four equivalent Cs(2)Cu12Te12 cuboctahedra and faces with six equivalent Cs(1)Cu16Te12 tetrahedra. In the second Cs site, Cs(2) is bonded to twelve equivalent Cu(2) and twelve equivalent Te(1) atoms to form distorted face-sharing CsCu12Te12 cuboctahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 8-coordinate geometry to one Cs(1), three equivalent Cu(2), one Te(2), and three equivalent Te(1) atoms. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one Cs(2), two equivalent Cs(1), two equivalent Cu(1), and four equivalent Te(1) atoms. There are two inequivalent Te sites. In the first Te site, Te(2) is bonded in a body-centered cubic geometry to eight equivalent Cu(1) atoms. In the second Te site, Te(1) is bonded in a 6-coordinate geometry to one Cs(2), two equivalent Cs(1), two equivalent Cu(1), and four equivalent Cu(2) atoms.
Cs3Cu20Te13 crystallizes in the cubic Fm-3 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to four equivalent Cu(1), twelve equivalent Cu(2), and twelve equivalent Te(1) atoms to form distorted CsCu16Te12 tetrahedra that share faces with four equivalent Cs(2)Cu12Te12 cuboctahedra and faces with six equivalent Cs(1)Cu16Te12 tetrahedra. All Cs(1)-Cu(1) bond lengths are 3.78 Å. All Cs(1)-Cu(2) bond lengths are 4.16 Å. All Cs(1)-Te(1) bond lengths are 4.18 Å. In the second Cs site, Cs(2) is bonded to twelve equivalent Cu(2) and twelve equivalent Te(1) atoms to form distorted face-sharing CsCu12Te12 cuboctahedra. All Cs(2)-Cu(2) bond lengths are 4.26 Å. All Cs(2)-Te(1) bond lengths are 4.09 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 8-coordinate geometry to one Cs(1), three equivalent Cu(2), one Te(2), and three equivalent Te(1) atoms. All Cu(1)-Cu(2) bond lengths are 2.62 Å. The Cu(1)-Te(2) bond length is 2.68 Å. All Cu(1)-Te(1) bond lengths are 2.76 Å. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one Cs(2), two equivalent Cs(1), two equivalent Cu(1), and four equivalent Te(1) atoms. There are a spread of Cu(2)-Te(1) bond distances ranging from 2.63-2.65 Å. There are two inequivalent Te sites. In the first Te site, Te(2) is bonded in a body-centered cubic geometry to eight equivalent Cu(1) atoms. In the second Te site, Te(1) is bonded in a 6-coordinate geometry to one Cs(2), two equivalent Cs(1), two equivalent Cu(1), and four equivalent Cu(2) atoms.