Ba3Ta2S8 crystallizes in the monoclinic P2/m space group. There are five inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted body-centered cubic geometry to two equivalent S(8), four equivalent S(1), and four equivalent S(2) atoms. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one S(8), two equivalent S(1), two equivalent S(4), two equivalent S(5), and four equivalent S(3) atoms. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent S(2), two equivalent S(3), two equivalent S(4), two equivalent S(6), and two equivalent S(7) atoms. In the fourth Ba site, Ba(4) is bonded in a 10-coordinate geometry to two equivalent S(1), two equivalent S(2), two equivalent S(3), two equivalent S(6), and two equivalent S(7) atoms. In the fifth Ba site, Ba(5) is bonded in a 11-coordinate geometry to one S(5), two equivalent S(1), two equivalent S(2), two equivalent S(8), and four equivalent S(4) atoms. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent S(8) and four equivalent S(4) atoms to form face-sharing TaS6 octahedra. In the second Ta site, Ta(2) is bonded to two equivalent S(5) and four equivalent S(3) atoms to form face-sharing TaS6 octahedra. In the third Ta site, Ta(3) is bonded to one S(6), one S(8), two equivalent S(2), and two equivalent S(4) atoms to form distorted face-sharing TaS6 octahedra. In the fourth Ta site, Ta(4) is bonded to one S(5), one S(7), two equivalent S(1), and two equivalent S(3) atoms to form distorted face-sharing TaS6 octahedra. There are eight inequivalent S sites. In the first S site, S(6) is bonded to two equivalent Ba(3), two equivalent Ba(4), and one Ta(3) atom to form distorted SBa4Ta square pyramids that share corners with four equivalent S(3)Ba4Ta2 octahedra, corners with two equivalent S(6)Ba4Ta square pyramids, edges with two equivalent S(3)Ba4Ta2 octahedra, and  an edgeedge with one S(6)Ba4Ta square pyramid. The corner-sharing octahedral tilt angles range from 42-59°. In the second S site, S(7) is bonded in a 5-coordinate geometry to two equivalent Ba(3), two equivalent Ba(4), and one Ta(4) atom. In the third S site, S(8) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), two equivalent Ba(5), one Ta(1), and one Ta(3) atom. In the fourth S site, S(1) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Ba(5), and one Ta(4) atom. In the fifth S site, S(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), one Ba(4), one Ba(5), and one Ta(3) atom. In the sixth S site, S(3) is bonded to one Ba(3), one Ba(4), two equivalent Ba(2), one Ta(2), and one Ta(4) atom to form distorted SBa4Ta2 octahedra that share  a cornercorner with one S(3)Ba4Ta2 octahedra, corners with two equivalent S(6)Ba4Ta square pyramids,  an edgeedge with one S(3)Ba4Ta2 octahedra,  an edgeedge with one S(6)Ba4Ta square pyramid, and faces with three equivalent S(3)Ba4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the seventh S site, S(4) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(5), one Ta(1), and one Ta(3) atom. In the eighth S site, S(5) is bonded in a 5-coordinate geometry to one Ba(5), two equivalent Ba(2), one Ta(2), and one Ta(4) atom.
Ba3Ta2S8 crystallizes in the monoclinic P2/m space group. There are five inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted body-centered cubic geometry to two equivalent S(8), four equivalent S(1), and four equivalent S(2) atoms. Both Ba(1)-S(8) bond lengths are 3.75 Å. All Ba(1)-S(1) bond lengths are 3.29 Å. All Ba(1)-S(2) bond lengths are 3.28 Å. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one S(8), two equivalent S(1), two equivalent S(4), two equivalent S(5), and four equivalent S(3) atoms. The Ba(2)-S(8) bond length is 3.21 Å. Both Ba(2)-S(1) bond lengths are 3.52 Å. Both Ba(2)-S(4) bond lengths are 3.49 Å. Both Ba(2)-S(5) bond lengths are 3.47 Å. There are two shorter (3.41 Å) and two longer (3.42 Å) Ba(2)-S(3) bond lengths. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent S(2), two equivalent S(3), two equivalent S(4), two equivalent S(6), and two equivalent S(7) atoms. Both Ba(3)-S(2) bond lengths are 3.51 Å. Both Ba(3)-S(3) bond lengths are 3.50 Å. Both Ba(3)-S(4) bond lengths are 3.32 Å. Both Ba(3)-S(6) bond lengths are 3.51 Å. There is one shorter (3.21 Å) and one longer (3.47 Å) Ba(3)-S(7) bond length. In the fourth Ba site, Ba(4) is bonded in a 10-coordinate geometry to two equivalent S(1), two equivalent S(2), two equivalent S(3), two equivalent S(6), and two equivalent S(7) atoms. Both Ba(4)-S(1) bond lengths are 3.20 Å. Both Ba(4)-S(2) bond lengths are 3.52 Å. Both Ba(4)-S(3) bond lengths are 3.43 Å. There is one shorter (3.22 Å) and one longer (3.30 Å) Ba(4)-S(6) bond length. Both Ba(4)-S(7) bond lengths are 3.50 Å. In the fifth Ba site, Ba(5) is bonded in a 11-coordinate geometry to one S(5), two equivalent S(1), two equivalent S(2), two equivalent S(8), and four equivalent S(4) atoms. The Ba(5)-S(5) bond length is 3.20 Å. Both Ba(5)-S(1) bond lengths are 3.45 Å. Both Ba(5)-S(2) bond lengths are 3.29 Å. Both Ba(5)-S(8) bond lengths are 3.47 Å. There are two shorter (3.38 Å) and two longer (3.62 Å) Ba(5)-S(4) bond lengths. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent S(8) and four equivalent S(4) atoms to form face-sharing TaS6 octahedra. Both Ta(1)-S(8) bond lengths are 2.40 Å. All Ta(1)-S(4) bond lengths are 2.46 Å. In the second Ta site, Ta(2) is bonded to two equivalent S(5) and four equivalent S(3) atoms to form face-sharing TaS6 octahedra. Both Ta(2)-S(5) bond lengths are 2.41 Å. All Ta(2)-S(3) bond lengths are 2.46 Å. In the third Ta site, Ta(3) is bonded to one S(6), one S(8), two equivalent S(2), and two equivalent S(4) atoms to form distorted face-sharing TaS6 octahedra. The Ta(3)-S(6) bond length is 2.34 Å. The Ta(3)-S(8) bond length is 2.63 Å. Both Ta(3)-S(2) bond lengths are 2.29 Å. Both Ta(3)-S(4) bond lengths are 2.66 Å. In the fourth Ta site, Ta(4) is bonded to one S(5), one S(7), two equivalent S(1), and two equivalent S(3) atoms to form distorted face-sharing TaS6 octahedra. The Ta(4)-S(5) bond length is 2.66 Å. The Ta(4)-S(7) bond length is 2.33 Å. Both Ta(4)-S(1) bond lengths are 2.29 Å. Both Ta(4)-S(3) bond lengths are 2.66 Å. There are eight inequivalent S sites. In the first S site, S(6) is bonded to two equivalent Ba(3), two equivalent Ba(4), and one Ta(3) atom to form distorted SBa4Ta square pyramids that share corners with four equivalent S(3)Ba4Ta2 octahedra, corners with two equivalent S(6)Ba4Ta square pyramids, edges with two equivalent S(3)Ba4Ta2 octahedra, and  an edgeedge with one S(6)Ba4Ta square pyramid. The corner-sharing octahedral tilt angles range from 42-59°. In the second S site, S(7) is bonded in a 5-coordinate geometry to two equivalent Ba(3), two equivalent Ba(4), and one Ta(4) atom. In the third S site, S(8) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), two equivalent Ba(5), one Ta(1), and one Ta(3) atom. In the fourth S site, S(1) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Ba(5), and one Ta(4) atom. In the fifth S site, S(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), one Ba(4), one Ba(5), and one Ta(3) atom. In the sixth S site, S(3) is bonded to one Ba(3), one Ba(4), two equivalent Ba(2), one Ta(2), and one Ta(4) atom to form distorted SBa4Ta2 octahedra that share  a cornercorner with one S(3)Ba4Ta2 octahedra, corners with two equivalent S(6)Ba4Ta square pyramids,  an edgeedge with one S(3)Ba4Ta2 octahedra,  an edgeedge with one S(6)Ba4Ta square pyramid, and faces with three equivalent S(3)Ba4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the seventh S site, S(4) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(5), one Ta(1), and one Ta(3) atom. In the eighth S site, S(5) is bonded in a 5-coordinate geometry to one Ba(5), two equivalent Ba(2), one Ta(2), and one Ta(4) atom.