TlCu7Se4 crystallizes in the triclinic P1 space group. There are seven inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to two equivalent Cu(5), one Se(1), and two equivalent Se(2) atoms. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to two equivalent Cu(5), one Se(1), one Se(3), and two equivalent Se(4) atoms. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(4) atoms. In the fourth Cu site, Cu(4) is bonded in a 3-coordinate geometry to one Cu(5), one Se(3), and two equivalent Se(1) atoms. In the fifth Cu site, Cu(5) is bonded in a 9-coordinate geometry to one Cu(4), two equivalent Cu(1), two equivalent Cu(2), one Se(2), one Se(4), and two equivalent Se(1) atoms. In the sixth Cu site, Cu(6) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(2) atoms. In the seventh Cu site, Cu(7) is bonded in a distorted trigonal non-coplanar geometry to one Se(4) and two equivalent Se(3) atoms. Tl(1) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(1) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 8-coordinate geometry to one Cu(1), one Cu(2), two equivalent Cu(4), two equivalent Cu(5), and two equivalent Tl(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to one Cu(3), one Cu(5), two equivalent Cu(1), and two equivalent Cu(6) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one Cu(2), one Cu(4), one Cu(6), two equivalent Cu(7), and one Tl(1) atom. In the fourth Se site, Se(4) is bonded in a 8-coordinate geometry to one Cu(5), one Cu(6), one Cu(7), two equivalent Cu(2), two equivalent Cu(3), and one Tl(1) atom.
TlCu7Se4 crystallizes in the triclinic P1 space group. There are seven inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to two equivalent Cu(5), one Se(1), and two equivalent Se(2) atoms. There is one shorter (2.61 Å) and one longer (2.65 Å) Cu(1)-Cu(5) bond length. The Cu(1)-Se(1) bond length is 2.43 Å. There is one shorter (2.60 Å) and one longer (2.65 Å) Cu(1)-Se(2) bond length. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to two equivalent Cu(5), one Se(1), one Se(3), and two equivalent Se(4) atoms. There is one shorter (2.71 Å) and one longer (2.73 Å) Cu(2)-Cu(5) bond length. The Cu(2)-Se(1) bond length is 2.40 Å. The Cu(2)-Se(3) bond length is 2.59 Å. There is one shorter (2.53 Å) and one longer (2.76 Å) Cu(2)-Se(4) bond length. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(4) atoms. The Cu(3)-Se(2) bond length is 2.44 Å. There is one shorter (2.53 Å) and one longer (2.63 Å) Cu(3)-Se(4) bond length. In the fourth Cu site, Cu(4) is bonded in a 3-coordinate geometry to one Cu(5), one Se(3), and two equivalent Se(1) atoms. The Cu(4)-Cu(5) bond length is 2.51 Å. The Cu(4)-Se(3) bond length is 2.38 Å. There is one shorter (2.51 Å) and one longer (2.59 Å) Cu(4)-Se(1) bond length. In the fifth Cu site, Cu(5) is bonded in a 9-coordinate geometry to one Cu(4), two equivalent Cu(1), two equivalent Cu(2), one Se(2), one Se(4), and two equivalent Se(1) atoms. The Cu(5)-Se(2) bond length is 2.49 Å. The Cu(5)-Se(4) bond length is 2.46 Å. There is one shorter (2.71 Å) and one longer (2.77 Å) Cu(5)-Se(1) bond length. In the sixth Cu site, Cu(6) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(2) atoms. The Cu(6)-Se(3) bond length is 2.41 Å. The Cu(6)-Se(4) bond length is 2.54 Å. There is one shorter (2.49 Å) and one longer (2.71 Å) Cu(6)-Se(2) bond length. In the seventh Cu site, Cu(7) is bonded in a distorted trigonal non-coplanar geometry to one Se(4) and two equivalent Se(3) atoms. The Cu(7)-Se(4) bond length is 2.49 Å. There is one shorter (2.45 Å) and one longer (2.49 Å) Cu(7)-Se(3) bond length. Tl(1) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(1) atoms. The Tl(1)-Se(3) bond length is 3.32 Å. The Tl(1)-Se(4) bond length is 3.32 Å. Both Tl(1)-Se(1) bond lengths are 3.30 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 8-coordinate geometry to one Cu(1), one Cu(2), two equivalent Cu(4), two equivalent Cu(5), and two equivalent Tl(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to one Cu(3), one Cu(5), two equivalent Cu(1), and two equivalent Cu(6) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one Cu(2), one Cu(4), one Cu(6), two equivalent Cu(7), and one Tl(1) atom. In the fourth Se site, Se(4) is bonded in a 8-coordinate geometry to one Cu(5), one Cu(6), one Cu(7), two equivalent Cu(2), two equivalent Cu(3), and one Tl(1) atom.