Ti4NiS8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form TiS6 octahedra that share corners with four equivalent Ni(1)S6 octahedra, edges with two equivalent Ti(1)S6 octahedra, and edges with four equivalent Ti(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the second Ti site, Ti(2) is bonded to one S(1), one S(2), and four equivalent S(3) atoms to form TiS6 octahedra that share corners with two equivalent Ni(1)S6 octahedra, edges with two equivalent Ti(2)S6 octahedra, edges with four equivalent Ti(1)S6 octahedra, and  a faceface with one Ni(1)S6 octahedra. The corner-sharing octahedral tilt angles are 49°. Ni(1) is bonded to two equivalent S(1) and four equivalent S(3) atoms to form NiS6 octahedra that share corners with four equivalent Ti(2)S6 octahedra, corners with eight equivalent Ti(1)S6 octahedra, and faces with two equivalent Ti(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-49°. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(1), and one Ni(1) atom. In the second S site, S(2) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(1) atoms. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Ti(1), two equivalent Ti(2), and one Ni(1) atom.
Ti4NiS8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form TiS6 octahedra that share corners with four equivalent Ni(1)S6 octahedra, edges with two equivalent Ti(1)S6 octahedra, and edges with four equivalent Ti(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. Both Ti(1)-S(1) bond lengths are 2.45 Å. Both Ti(1)-S(2) bond lengths are 2.40 Å. Both Ti(1)-S(3) bond lengths are 2.45 Å. In the second Ti site, Ti(2) is bonded to one S(1), one S(2), and four equivalent S(3) atoms to form TiS6 octahedra that share corners with two equivalent Ni(1)S6 octahedra, edges with two equivalent Ti(2)S6 octahedra, edges with four equivalent Ti(1)S6 octahedra, and  a faceface with one Ni(1)S6 octahedra. The corner-sharing octahedral tilt angles are 49°. The Ti(2)-S(1) bond length is 2.45 Å. The Ti(2)-S(2) bond length is 2.39 Å. There are two shorter (2.42 Å) and two longer (2.46 Å) Ti(2)-S(3) bond lengths. Ni(1) is bonded to two equivalent S(1) and four equivalent S(3) atoms to form NiS6 octahedra that share corners with four equivalent Ti(2)S6 octahedra, corners with eight equivalent Ti(1)S6 octahedra, and faces with two equivalent Ti(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-49°. Both Ni(1)-S(1) bond lengths are 2.41 Å. All Ni(1)-S(3) bond lengths are 2.40 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(1), and one Ni(1) atom. In the second S site, S(2) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(1) atoms. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Ti(1), two equivalent Ti(2), and one Ni(1) atom.