Co6Mo6C crystallizes in the cubic Fd-3m space group. Mo(1) is bonded in a distorted single-bond geometry to two equivalent Co(2), four equivalent Co(1), and one C(1) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 12-coordinate geometry to six equivalent Mo(1), three equivalent Co(1), and three equivalent Co(2) atoms. In the second Co site, Co(2) is bonded to six equivalent Mo(1) and six equivalent Co(1) atoms to form CoCo6Mo6 cuboctahedra that share corners with six equivalent C(1)Mo6 octahedra and faces with six equivalent Co(2)Co6Mo6 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. C(1) is bonded to six equivalent Mo(1) atoms to form CMo6 octahedra that share corners with twelve equivalent Co(2)Co6Mo6 cuboctahedra.
Co6Mo6C crystallizes in the cubic Fd-3m space group. Mo(1) is bonded in a distorted single-bond geometry to two equivalent Co(2), four equivalent Co(1), and one C(1) atom. Both Mo(1)-Co(2) bond lengths are 2.72 Å. There are two shorter (2.59 Å) and two longer (2.70 Å) Mo(1)-Co(1) bond lengths. The Mo(1)-C(1) bond length is 2.15 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 12-coordinate geometry to six equivalent Mo(1), three equivalent Co(1), and three equivalent Co(2) atoms. All Co(1)-Co(1) bond lengths are 2.54 Å. All Co(1)-Co(2) bond lengths are 2.35 Å. In the second Co site, Co(2) is bonded to six equivalent Mo(1) and six equivalent Co(1) atoms to form CoCo6Mo6 cuboctahedra that share corners with six equivalent C(1)Mo6 octahedra and faces with six equivalent Co(2)Co6Mo6 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. C(1) is bonded to six equivalent Mo(1) atoms to form CMo6 octahedra that share corners with twelve equivalent Co(2)Co6Mo6 cuboctahedra.