Ta6Nb3Te2S3 crystallizes in the monoclinic P2_1/m space group. There are six inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 3-coordinate geometry to one S(1), one S(3), and two equivalent S(2) atoms. In the second Ta site, Ta(2) is bonded in a 4-coordinate geometry to two equivalent Te(1) and two equivalent Te(2) atoms. In the third Ta site, Ta(3) is bonded in a distorted body-centered cubic geometry to two equivalent Ta(3), two equivalent Ta(4), two equivalent Ta(5), and two equivalent Ta(6) atoms. In the fourth Ta site, Ta(4) is bonded in a distorted single-bond geometry to two equivalent Ta(3), one Te(2), and one S(2) atom. In the fifth Ta site, Ta(5) is bonded in a distorted single-bond geometry to two equivalent Ta(3), one Te(1), and one S(1) atom. In the sixth Ta site, Ta(6) is bonded in an L-shaped geometry to two equivalent Ta(3) and two equivalent S(1) atoms. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 5-coordinate geometry to two equivalent S(3) and three equivalent S(1) atoms. In the second Nb site, Nb(2) is bonded in a 3-coordinate geometry to two equivalent Te(2) and three equivalent S(2) atoms. In the third Nb site, Nb(3) is bonded in a 3-coordinate geometry to two equivalent Te(1), one S(3), and two equivalent S(1) atoms. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 5-coordinate geometry to one Ta(5), two equivalent Ta(2), and two equivalent Nb(3) atoms. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one Ta(4), two equivalent Ta(2), and two equivalent Nb(2) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 9-coordinate geometry to one Ta(1), one Ta(5), two equivalent Ta(6), two equivalent Nb(3), and three equivalent Nb(1) atoms. In the second S site, S(2) is bonded in a 6-coordinate geometry to one Ta(4), two equivalent Ta(1), and three equivalent Nb(2) atoms. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Ta(1), one Nb(3), and two equivalent Nb(1) atoms.
Ta6Nb3Te2S3 crystallizes in the monoclinic P2_1/m space group. There are six inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 3-coordinate geometry to one S(1), one S(3), and two equivalent S(2) atoms. The Ta(1)-S(1) bond length is 3.06 Å. The Ta(1)-S(3) bond length is 2.48 Å. Both Ta(1)-S(2) bond lengths are 2.51 Å. In the second Ta site, Ta(2) is bonded in a 4-coordinate geometry to two equivalent Te(1) and two equivalent Te(2) atoms. Both Ta(2)-Te(1) bond lengths are 2.88 Å. Both Ta(2)-Te(2) bond lengths are 2.89 Å. In the third Ta site, Ta(3) is bonded in a distorted body-centered cubic geometry to two equivalent Ta(3), two equivalent Ta(4), two equivalent Ta(5), and two equivalent Ta(6) atoms. Both Ta(3)-Ta(3) bond lengths are 2.92 Å. Both Ta(3)-Ta(4) bond lengths are 2.85 Å. Both Ta(3)-Ta(5) bond lengths are 2.86 Å. Both Ta(3)-Ta(6) bond lengths are 2.85 Å. In the fourth Ta site, Ta(4) is bonded in a distorted single-bond geometry to two equivalent Ta(3), one Te(2), and one S(2) atom. The Ta(4)-Te(2) bond length is 3.11 Å. The Ta(4)-S(2) bond length is 2.71 Å. In the fifth Ta site, Ta(5) is bonded in a distorted single-bond geometry to two equivalent Ta(3), one Te(1), and one S(1) atom. The Ta(5)-Te(1) bond length is 3.10 Å. The Ta(5)-S(1) bond length is 2.65 Å. In the sixth Ta site, Ta(6) is bonded in an L-shaped geometry to two equivalent Ta(3) and two equivalent S(1) atoms. Both Ta(6)-S(1) bond lengths are 2.53 Å. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 5-coordinate geometry to two equivalent S(3) and three equivalent S(1) atoms. Both Nb(1)-S(3) bond lengths are 2.52 Å. There are two shorter (2.54 Å) and one longer (2.91 Å) Nb(1)-S(1) bond length. In the second Nb site, Nb(2) is bonded in a 3-coordinate geometry to two equivalent Te(2) and three equivalent S(2) atoms. Both Nb(2)-Te(2) bond lengths are 2.89 Å. There is one shorter (2.52 Å) and two longer (2.55 Å) Nb(2)-S(2) bond lengths. In the third Nb site, Nb(3) is bonded in a 3-coordinate geometry to two equivalent Te(1), one S(3), and two equivalent S(1) atoms. Both Nb(3)-Te(1) bond lengths are 2.94 Å. The Nb(3)-S(3) bond length is 2.49 Å. Both Nb(3)-S(1) bond lengths are 2.50 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 5-coordinate geometry to one Ta(5), two equivalent Ta(2), and two equivalent Nb(3) atoms. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one Ta(4), two equivalent Ta(2), and two equivalent Nb(2) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 9-coordinate geometry to one Ta(1), one Ta(5), two equivalent Ta(6), two equivalent Nb(3), and three equivalent Nb(1) atoms. In the second S site, S(2) is bonded in a 6-coordinate geometry to one Ta(4), two equivalent Ta(1), and three equivalent Nb(2) atoms. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Ta(1), one Nb(3), and two equivalent Nb(1) atoms.