Nb6Ni6O crystallizes in the cubic Fd-3m space group. Nb(1) is bonded in a single-bond geometry to two equivalent Ni(2), four equivalent Ni(1), and one O(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 Nb(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the second Ni site, Ni(2) is bonded to six equivalent Nb(1) and six equivalent Ni(1) atoms to form NiNb6Ni6 cuboctahedra that share corners with six equivalent O(1)Nb6 octahedra and faces with six equivalent Ni(2)Nb6Ni6 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. O(1) is bonded to six equivalent Nb(1) atoms to form ONb6 octahedra that share corners with twelve equivalent Ni(2)Nb6Ni6 cuboctahedra.
Nb6Ni6O crystallizes in the cubic Fd-3m space group. Nb(1) is bonded in a single-bond geometry to two equivalent Ni(2), four equivalent Ni(1), and one O(1) atom. Both Nb(1)-Ni(2) bond lengths are 2.78 Å. There are two shorter (2.69 Å) and two longer (2.76 Å) Nb(1)-Ni(1) bond lengths. The Nb(1)-O(1) bond length is 2.23 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to six equivalent Nb(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 2.40 Å. In the second Ni site, Ni(2) is bonded to six equivalent Nb(1) and six equivalent Ni(1) atoms to form NiNb6Ni6 cuboctahedra that share corners with six equivalent O(1)Nb6 octahedra and faces with six equivalent Ni(2)Nb6Ni6 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. O(1) is bonded to six equivalent Nb(1) atoms to form ONb6 octahedra that share corners with twelve equivalent Ni(2)Nb6Ni6 cuboctahedra.