Co3S is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Co(1) is bonded to eight equivalent Co(1) and four equivalent S(1) atoms to form distorted CoCo8S4 cuboctahedra that share corners with four equivalent S(1)Co12 cuboctahedra, corners with fourteen equivalent Co(1)Co8S4 cuboctahedra, edges with six equivalent S(1)Co12 cuboctahedra, edges with twelve equivalent Co(1)Co8S4 cuboctahedra, faces with four equivalent S(1)Co12 cuboctahedra, and faces with sixteen equivalent Co(1)Co8S4 cuboctahedra. S(1) is bonded to twelve equivalent Co(1) atoms to form SCo12 cuboctahedra that share corners with six equivalent S(1)Co12 cuboctahedra, corners with twelve equivalent Co(1)Co8S4 cuboctahedra, edges with eighteen equivalent Co(1)Co8S4 cuboctahedra, faces with eight equivalent S(1)Co12 cuboctahedra, and faces with twelve equivalent Co(1)Co8S4 cuboctahedra.
Co3S is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Co(1) is bonded to eight equivalent Co(1) and four equivalent S(1) atoms to form distorted CoCo8S4 cuboctahedra that share corners with four equivalent S(1)Co12 cuboctahedra, corners with fourteen equivalent Co(1)Co8S4 cuboctahedra, edges with six equivalent S(1)Co12 cuboctahedra, edges with twelve equivalent Co(1)Co8S4 cuboctahedra, faces with four equivalent S(1)Co12 cuboctahedra, and faces with sixteen equivalent Co(1)Co8S4 cuboctahedra. There are a spread of Co(1)-Co(1) bond distances ranging from 2.47-2.60 Å. There are two shorter (2.46 Å) and two longer (2.58 Å) Co(1)-S(1) bond lengths. S(1) is bonded to twelve equivalent Co(1) atoms to form SCo12 cuboctahedra that share corners with six equivalent S(1)Co12 cuboctahedra, corners with twelve equivalent Co(1)Co8S4 cuboctahedra, edges with eighteen equivalent Co(1)Co8S4 cuboctahedra, faces with eight equivalent S(1)Co12 cuboctahedra, and faces with twelve equivalent Co(1)Co8S4 cuboctahedra.