Hf2ON2 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent N(1) and four equivalent N(2) atoms to form a mixture of corner and edge-sharing HfN6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to two equivalent N(1), two equivalent N(2), and three equivalent O(1) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form NHf4 tetrahedra that share corners with two equivalent N(2)Hf6 octahedra, corners with four equivalent N(1)Hf4 tetrahedra, and edges with five equivalent N(2)Hf6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the second N site, N(2) is bonded to two equivalent Hf(2) and four equivalent Hf(1) atoms to form NHf6 octahedra that share corners with two equivalent N(2)Hf6 octahedra, corners with two equivalent N(1)Hf4 tetrahedra, edges with six equivalent N(2)Hf6 octahedra, and edges with five equivalent N(1)Hf4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. O(1) is bonded in a trigonal non-coplanar geometry to three equivalent Hf(2) atoms.
Hf2ON2 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent N(1) and four equivalent N(2) atoms to form a mixture of corner and edge-sharing HfN6 octahedra. The corner-sharing octahedral tilt angles are 4°. Both Hf(1)-N(1) bond lengths are 2.11 Å. There are a spread of Hf(1)-N(2) bond distances ranging from 2.13-2.44 Å. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to two equivalent N(1), two equivalent N(2), and three equivalent O(1) atoms. There is one shorter (2.17 Å) and one longer (2.32 Å) Hf(2)-N(1) bond length. Both Hf(2)-N(2) bond lengths are 2.62 Å. There are two shorter (2.01 Å) and one longer (2.21 Å) Hf(2)-O(1) bond length. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form NHf4 tetrahedra that share corners with two equivalent N(2)Hf6 octahedra, corners with four equivalent N(1)Hf4 tetrahedra, and edges with five equivalent N(2)Hf6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the second N site, N(2) is bonded to two equivalent Hf(2) and four equivalent Hf(1) atoms to form NHf6 octahedra that share corners with two equivalent N(2)Hf6 octahedra, corners with two equivalent N(1)Hf4 tetrahedra, edges with six equivalent N(2)Hf6 octahedra, and edges with five equivalent N(1)Hf4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. O(1) is bonded in a trigonal non-coplanar geometry to three equivalent Hf(2) atoms.