Ta8(CuS8)3 crystallizes in the monoclinic Pm space group. There are eight inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one S(1), one S(13), two equivalent S(11), and two equivalent S(8) atoms. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to one S(14), one S(2), two equivalent S(12), and two equivalent S(7) atoms. In the third Ta site, Ta(3) is bonded in a 6-coordinate geometry to one S(15), one S(3), two equivalent S(6), and two equivalent S(9) atoms. In the fourth Ta site, Ta(4) is bonded in a 6-coordinate geometry to one S(16), one S(4), two equivalent S(10), and two equivalent S(5) atoms. In the fifth Ta site, Ta(5) is bonded in a 8-coordinate geometry to one S(1), one S(9), two equivalent S(20), two equivalent S(24), and two equivalent S(3) atoms. In the sixth Ta site, Ta(6) is bonded in a 8-coordinate geometry to one S(10), one S(2), two equivalent S(19), two equivalent S(23), and two equivalent S(4) atoms. In the seventh Ta site, Ta(7) is bonded in a 8-coordinate geometry to one S(11), one S(3), two equivalent S(1), two equivalent S(18), and two equivalent S(22) atoms. In the eighth Ta site, Ta(8) is bonded in a 8-coordinate geometry to one S(12), one S(4), two equivalent S(17), two equivalent S(2), and two equivalent S(21) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(10), one S(6), and two equivalent S(15) atoms to form distorted corner-sharing CuS4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(11), one S(7), and two equivalent S(14) atoms to form distorted corner-sharing CuS4 tetrahedra. In the third Cu site, Cu(3) is bonded to one S(12), one S(8), and two equivalent S(13) atoms to form distorted corner-sharing CuS4 tetrahedra. There are twenty-four inequivalent S sites. In the first S site, S(1) is bonded to one Ta(1), one Ta(5), and two equivalent Ta(7) atoms to form distorted STa4 trigonal pyramids that share corners with two equivalent S(1)Ta4 trigonal pyramids, edges with two equivalent S(11)Ta3Cu tetrahedra, and edges with two equivalent S(3)Ta4 trigonal pyramids. In the second S site, S(2) is bonded to one Ta(2), one Ta(6), and two equivalent Ta(8) atoms to form distorted STa4 trigonal pyramids that share  a cornercorner with one S(10)Ta3Cu tetrahedra, corners with two equivalent S(2)Ta4 trigonal pyramids, edges with two equivalent S(12)Ta3Cu tetrahedra, and edges with two equivalent S(4)Ta4 trigonal pyramids. In the third S site, S(3) is bonded to one Ta(3), one Ta(7), and two equivalent Ta(5) atoms to form distorted STa4 trigonal pyramids that share  a cornercorner with one S(11)Ta3Cu tetrahedra, corners with two equivalent S(3)Ta4 trigonal pyramids, and edges with two equivalent S(1)Ta4 trigonal pyramids. In the fourth S site, S(4) is bonded to one Ta(4), one Ta(8), and two equivalent Ta(6) atoms to form distorted STa4 trigonal pyramids that share  a cornercorner with one S(12)Ta3Cu tetrahedra, corners with two equivalent S(4)Ta4 trigonal pyramids, edges with two equivalent S(10)Ta3Cu tetrahedra, and edges with two equivalent S(2)Ta4 trigonal pyramids. In the fifth S site, S(5) is bonded in an L-shaped geometry to two equivalent Ta(4) atoms. In the sixth S site, S(6) is bonded in a distorted T-shaped geometry to two equivalent Ta(3) and one Cu(1) atom. In the seventh S site, S(7) is bonded in a distorted T-shaped geometry to two equivalent Ta(2) and one Cu(2) atom. In the eighth S site, S(8) is bonded in a distorted T-shaped geometry to two equivalent Ta(1) and one Cu(3) atom. In the ninth S site, S(9) is bonded in a trigonal non-coplanar geometry to one Ta(5) and two equivalent Ta(3) atoms. In the tenth S site, S(10) is bonded to one Ta(6), two equivalent Ta(4), and one Cu(1) atom to form distorted STa3Cu tetrahedra that share corners with two equivalent S(10)Ta3Cu tetrahedra,  a cornercorner with one S(2)Ta4 trigonal pyramid, and edges with two equivalent S(4)Ta4 trigonal pyramids. In the eleventh S site, S(11) is bonded to one Ta(7), two equivalent Ta(1), and one Cu(2) atom to form distorted STa3Cu tetrahedra that share corners with two equivalent S(11)Ta3Cu tetrahedra,  a cornercorner with one S(3)Ta4 trigonal pyramid, and edges with two equivalent S(1)Ta4 trigonal pyramids. In the twelfth S site, S(12) is bonded to one Ta(8), two equivalent Ta(2), and one Cu(3) atom to form distorted STa3Cu tetrahedra that share corners with two equivalent S(12)Ta3Cu tetrahedra,  a cornercorner with one S(4)Ta4 trigonal pyramid, and edges with two equivalent S(2)Ta4 trigonal pyramids. In the thirteenth S site, S(13) is bonded in a distorted T-shaped geometry to one Ta(1) and two equivalent Cu(3) atoms. In the fourteenth S site, S(14) is bonded in a distorted T-shaped geometry to one Ta(2) and two equivalent Cu(2) atoms. In the fifteenth S site, S(15) is bonded in a distorted T-shaped geometry to one Ta(3) and two equivalent Cu(1) atoms. In the sixteenth S site, S(16) is bonded in a single-bond geometry to one Ta(4) atom. In the seventeenth S site, S(17) is bonded in a 3-coordinate geometry to two equivalent Ta(8) and one S(21) atom. In the eighteenth S site, S(18) is bonded in a 3-coordinate geometry to two equivalent Ta(7) and one S(22) atom. In the nineteenth S site, S(19) is bonded in a 3-coordinate geometry to two equivalent Ta(6) and one S(23) atom. In the twentieth S site, S(20) is bonded in a 3-coordinate geometry to two equivalent Ta(5) and one S(24) atom. In the twenty-first S site, S(21) is bonded in a 3-coordinate geometry to two equivalent Ta(8) and one S(17) atom. In the twenty-second S site, S(22) is bonded in a 3-coordinate geometry to two equivalent Ta(7) and one S(18) atom. In the twenty-third S site, S(23) is bonded in a 3-coordinate geometry to two equivalent Ta(6) and one S(19) atom. In the twenty-fourth S site, S(24) is bonded in a 3-coordinate geometry to two equivalent Ta(5) and one S(20) atom.
Ta8(CuS8)3 crystallizes in the monoclinic Pm space group. There are eight inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one S(1), one S(13), two equivalent S(11), and two equivalent S(8) atoms. The Ta(1)-S(1) bond length is 2.70 Å. The Ta(1)-S(13) bond length is 2.28 Å. Both Ta(1)-S(11) bond lengths are 2.54 Å. Both Ta(1)-S(8) bond lengths are 2.43 Å. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to one S(14), one S(2), two equivalent S(12), and two equivalent S(7) atoms. The Ta(2)-S(14) bond length is 2.28 Å. The Ta(2)-S(2) bond length is 2.70 Å. Both Ta(2)-S(12) bond lengths are 2.54 Å. Both Ta(2)-S(7) bond lengths are 2.43 Å. In the third Ta site, Ta(3) is bonded in a 6-coordinate geometry to one S(15), one S(3), two equivalent S(6), and two equivalent S(9) atoms. The Ta(3)-S(15) bond length is 2.27 Å. The Ta(3)-S(3) bond length is 2.73 Å. Both Ta(3)-S(6) bond lengths are 2.43 Å. Both Ta(3)-S(9) bond lengths are 2.50 Å. In the fourth Ta site, Ta(4) is bonded in a 6-coordinate geometry to one S(16), one S(4), two equivalent S(10), and two equivalent S(5) atoms. The Ta(4)-S(16) bond length is 2.16 Å. The Ta(4)-S(4) bond length is 2.81 Å. Both Ta(4)-S(10) bond lengths are 2.57 Å. Both Ta(4)-S(5) bond lengths are 2.38 Å. In the fifth Ta site, Ta(5) is bonded in a 8-coordinate geometry to one S(1), one S(9), two equivalent S(20), two equivalent S(24), and two equivalent S(3) atoms. The Ta(5)-S(1) bond length is 2.63 Å. The Ta(5)-S(9) bond length is 2.59 Å. Both Ta(5)-S(20) bond lengths are 2.54 Å. Both Ta(5)-S(24) bond lengths are 2.55 Å. Both Ta(5)-S(3) bond lengths are 2.50 Å. In the sixth Ta site, Ta(6) is bonded in a 8-coordinate geometry to one S(10), one S(2), two equivalent S(19), two equivalent S(23), and two equivalent S(4) atoms. The Ta(6)-S(10) bond length is 2.63 Å. The Ta(6)-S(2) bond length is 2.62 Å. Both Ta(6)-S(19) bond lengths are 2.54 Å. Both Ta(6)-S(23) bond lengths are 2.55 Å. Both Ta(6)-S(4) bond lengths are 2.49 Å. In the seventh Ta site, Ta(7) is bonded in a 8-coordinate geometry to one S(11), one S(3), two equivalent S(1), two equivalent S(18), and two equivalent S(22) atoms. The Ta(7)-S(11) bond length is 2.65 Å. The Ta(7)-S(3) bond length is 2.58 Å. Both Ta(7)-S(1) bond lengths are 2.51 Å. Both Ta(7)-S(18) bond lengths are 2.54 Å. Both Ta(7)-S(22) bond lengths are 2.55 Å. In the eighth Ta site, Ta(8) is bonded in a 8-coordinate geometry to one S(12), one S(4), two equivalent S(17), two equivalent S(2), and two equivalent S(21) atoms. The Ta(8)-S(12) bond length is 2.66 Å. The Ta(8)-S(4) bond length is 2.57 Å. Both Ta(8)-S(17) bond lengths are 2.53 Å. Both Ta(8)-S(2) bond lengths are 2.51 Å. Both Ta(8)-S(21) bond lengths are 2.55 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(10), one S(6), and two equivalent S(15) atoms to form distorted corner-sharing CuS4 tetrahedra. The Cu(1)-S(10) bond length is 2.28 Å. The Cu(1)-S(6) bond length is 2.28 Å. Both Cu(1)-S(15) bond lengths are 2.29 Å. In the second Cu site, Cu(2) is bonded to one S(11), one S(7), and two equivalent S(14) atoms to form distorted corner-sharing CuS4 tetrahedra. The Cu(2)-S(11) bond length is 2.29 Å. The Cu(2)-S(7) bond length is 2.27 Å. Both Cu(2)-S(14) bond lengths are 2.29 Å. In the third Cu site, Cu(3) is bonded to one S(12), one S(8), and two equivalent S(13) atoms to form distorted corner-sharing CuS4 tetrahedra. The Cu(3)-S(12) bond length is 2.28 Å. The Cu(3)-S(8) bond length is 2.27 Å. Both Cu(3)-S(13) bond lengths are 2.28 Å. There are twenty-four inequivalent S sites. In the first S site, S(1) is bonded to one Ta(1), one Ta(5), and two equivalent Ta(7) atoms to form distorted STa4 trigonal pyramids that share corners with two equivalent S(1)Ta4 trigonal pyramids, edges with two equivalent S(11)Ta3Cu tetrahedra, and edges with two equivalent S(3)Ta4 trigonal pyramids. In the second S site, S(2) is bonded to one Ta(2), one Ta(6), and two equivalent Ta(8) atoms to form distorted STa4 trigonal pyramids that share  a cornercorner with one S(10)Ta3Cu tetrahedra, corners with two equivalent S(2)Ta4 trigonal pyramids, edges with two equivalent S(12)Ta3Cu tetrahedra, and edges with two equivalent S(4)Ta4 trigonal pyramids. In the third S site, S(3) is bonded to one Ta(3), one Ta(7), and two equivalent Ta(5) atoms to form distorted STa4 trigonal pyramids that share  a cornercorner with one S(11)Ta3Cu tetrahedra, corners with two equivalent S(3)Ta4 trigonal pyramids, and edges with two equivalent S(1)Ta4 trigonal pyramids. In the fourth S site, S(4) is bonded to one Ta(4), one Ta(8), and two equivalent Ta(6) atoms to form distorted STa4 trigonal pyramids that share  a cornercorner with one S(12)Ta3Cu tetrahedra, corners with two equivalent S(4)Ta4 trigonal pyramids, edges with two equivalent S(10)Ta3Cu tetrahedra, and edges with two equivalent S(2)Ta4 trigonal pyramids. In the fifth S site, S(5) is bonded in an L-shaped geometry to two equivalent Ta(4) atoms. In the sixth S site, S(6) is bonded in a distorted T-shaped geometry to two equivalent Ta(3) and one Cu(1) atom. In the seventh S site, S(7) is bonded in a distorted T-shaped geometry to two equivalent Ta(2) and one Cu(2) atom. In the eighth S site, S(8) is bonded in a distorted T-shaped geometry to two equivalent Ta(1) and one Cu(3) atom. In the ninth S site, S(9) is bonded in a trigonal non-coplanar geometry to one Ta(5) and two equivalent Ta(3) atoms. In the tenth S site, S(10) is bonded to one Ta(6), two equivalent Ta(4), and one Cu(1) atom to form distorted STa3Cu tetrahedra that share corners with two equivalent S(10)Ta3Cu tetrahedra,  a cornercorner with one S(2)Ta4 trigonal pyramid, and edges with two equivalent S(4)Ta4 trigonal pyramids. In the eleventh S site, S(11) is bonded to one Ta(7), two equivalent Ta(1), and one Cu(2) atom to form distorted STa3Cu tetrahedra that share corners with two equivalent S(11)Ta3Cu tetrahedra,  a cornercorner with one S(3)Ta4 trigonal pyramid, and edges with two equivalent S(1)Ta4 trigonal pyramids. In the twelfth S site, S(12) is bonded to one Ta(8), two equivalent Ta(2), and one Cu(3) atom to form distorted STa3Cu tetrahedra that share corners with two equivalent S(12)Ta3Cu tetrahedra,  a cornercorner with one S(4)Ta4 trigonal pyramid, and edges with two equivalent S(2)Ta4 trigonal pyramids. In the thirteenth S site, S(13) is bonded in a distorted T-shaped geometry to one Ta(1) and two equivalent Cu(3) atoms. In the fourteenth S site, S(14) is bonded in a distorted T-shaped geometry to one Ta(2) and two equivalent Cu(2) atoms. In the fifteenth S site, S(15) is bonded in a distorted T-shaped geometry to one Ta(3) and two equivalent Cu(1) atoms. In the sixteenth S site, S(16) is bonded in a single-bond geometry to one Ta(4) atom. In the seventeenth S site, S(17) is bonded in a 3-coordinate geometry to two equivalent Ta(8) and one S(21) atom. The S(17)-S(21) bond length is 2.05 Å. In the eighteenth S site, S(18) is bonded in a 3-coordinate geometry to two equivalent Ta(7) and one S(22) atom. The S(18)-S(22) bond length is 2.04 Å. In the nineteenth S site, S(19) is bonded in a 3-coordinate geometry to two equivalent Ta(6) and one S(23) atom. The S(19)-S(23) bond length is 2.04 Å. In the twentieth S site, S(20) is bonded in a 3-coordinate geometry to two equivalent Ta(5) and one S(24) atom. The S(20)-S(24) bond length is 2.04 Å. In the twenty-first S site, S(21) is bonded in a 3-coordinate geometry to two equivalent Ta(8) and one S(17) atom. In the twenty-second S site, S(22) is bonded in a 3-coordinate geometry to two equivalent Ta(7) and one S(18) atom. In the twenty-third S site, S(23) is bonded in a 3-coordinate geometry to two equivalent Ta(6) and one S(19) atom. In the twenty-fourth S site, S(24) is bonded in a 3-coordinate geometry to two equivalent Ta(5) and one S(20) atom.