Ti2CoS4 crystallizes in the monoclinic C2/m space group. Ti(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form TiS6 octahedra that share corners with six equivalent Co(1)S6 octahedra, edges with six equivalent Ti(1)S6 octahedra, and  a faceface with one Co(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 48-49°. Co(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CoS6 octahedra that share corners with twelve equivalent Ti(1)S6 octahedra, edges with two equivalent Co(1)S6 octahedra, and faces with two equivalent Ti(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 48-49°. There are two inequivalent S sites. In the first S site, S(2) is bonded to three equivalent Ti(1) and two equivalent Co(1) atoms to form a mixture of distorted corner and edge-sharing STi3Co2 square pyramids. In the second S site, S(1) is bonded in a rectangular see-saw-like geometry to three equivalent Ti(1) and one Co(1) atom.
Ti2CoS4 crystallizes in the monoclinic C2/m space group. Ti(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form TiS6 octahedra that share corners with six equivalent Co(1)S6 octahedra, edges with six equivalent Ti(1)S6 octahedra, and  a faceface with one Co(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 48-49°. There are two shorter (2.42 Å) and one longer (2.43 Å) Ti(1)-S(1) bond length. There is one shorter (2.47 Å) and two longer (2.48 Å) Ti(1)-S(2) bond lengths. Co(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CoS6 octahedra that share corners with twelve equivalent Ti(1)S6 octahedra, edges with two equivalent Co(1)S6 octahedra, and faces with two equivalent Ti(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 48-49°. Both Co(1)-S(1) bond lengths are 2.37 Å. All Co(1)-S(2) bond lengths are 2.43 Å. There are two inequivalent S sites. In the first S site, S(2) is bonded to three equivalent Ti(1) and two equivalent Co(1) atoms to form a mixture of distorted corner and edge-sharing STi3Co2 square pyramids. In the second S site, S(1) is bonded in a rectangular see-saw-like geometry to three equivalent Ti(1) and one Co(1) atom.