Ni6W6C crystallizes in the cubic Fd-3m space group. W(1) is bonded in a 7-coordinate geometry to two equivalent Ni(2), four equivalent Ni(1), and one C(1) atom. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to six equivalent W(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the second Ni site, Ni(2) is bonded to six equivalent W(1) and six equivalent Ni(1) atoms to form NiNi6W6 cuboctahedra that share corners with six equivalent C(1)W6 octahedra and faces with six equivalent Ni(2)Ni6W6 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. C(1) is bonded to six equivalent W(1) atoms to form CW6 octahedra that share corners with twelve equivalent Ni(2)Ni6W6 cuboctahedra.
Ni6W6C crystallizes in the cubic Fd-3m space group. W(1) is bonded in a 7-coordinate geometry to two equivalent Ni(2), four equivalent Ni(1), and one C(1) atom. Both W(1)-Ni(2) bond lengths are 2.69 Å. There are two shorter (2.58 Å) and two longer (2.67 Å) W(1)-Ni(1) bond lengths. The W(1)-C(1) bond length is 2.18 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to six equivalent W(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. All Ni(1)-Ni(1) bond lengths are 2.56 Å. All Ni(1)-Ni(2) bond lengths are 2.35 Å. In the second Ni site, Ni(2) is bonded to six equivalent W(1) and six equivalent Ni(1) atoms to form NiNi6W6 cuboctahedra that share corners with six equivalent C(1)W6 octahedra and faces with six equivalent Ni(2)Ni6W6 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. C(1) is bonded to six equivalent W(1) atoms to form CW6 octahedra that share corners with twelve equivalent Ni(2)Ni6W6 cuboctahedra.