Hf2ON2 is beta indium sulfide-derived structured and crystallizes in the tetragonal I4_1/amd space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent N(1) and two equivalent O(1) atoms to form HfN4O2 octahedra that share corners with four equivalent Hf(3)N4 tetrahedra, edges with two equivalent Hf(1)N4O2 octahedra, and edges with four equivalent Hf(2)N4O2 octahedra. In the second Hf site, Hf(2) is bonded to one N(1), three equivalent N(2), and two equivalent O(1) atoms to form HfN4O2 octahedra that share corners with four equivalent Hf(3)N4 tetrahedra, edges with two equivalent Hf(1)N4O2 octahedra, and edges with four equivalent Hf(2)N4O2 octahedra. In the third Hf site, Hf(3) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form corner-sharing HfN4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are two inequivalent N sites. In the first N site, N(2) is bonded to one Hf(3) and three equivalent Hf(2) atoms to form a mixture of distorted corner and edge-sharing NHf4 trigonal pyramids. In the second N site, N(1) is bonded in a distorted rectangular see-saw-like geometry to one Hf(2), one Hf(3), and two equivalent Hf(1) atoms. O(1) is bonded in a distorted trigonal non-coplanar geometry to one Hf(1) and two equivalent Hf(2) atoms.
Hf2ON2 is beta indium sulfide-derived structured and crystallizes in the tetragonal I4_1/amd space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent N(1) and two equivalent O(1) atoms to form HfN4O2 octahedra that share corners with four equivalent Hf(3)N4 tetrahedra, edges with two equivalent Hf(1)N4O2 octahedra, and edges with four equivalent Hf(2)N4O2 octahedra. All Hf(1)-N(1) bond lengths are 2.21 Å. Both Hf(1)-O(1) bond lengths are 2.08 Å. In the second Hf site, Hf(2) is bonded to one N(1), three equivalent N(2), and two equivalent O(1) atoms to form HfN4O2 octahedra that share corners with four equivalent Hf(3)N4 tetrahedra, edges with two equivalent Hf(1)N4O2 octahedra, and edges with four equivalent Hf(2)N4O2 octahedra. The Hf(2)-N(1) bond length is 2.23 Å. There is one shorter (2.19 Å) and two longer (2.20 Å) Hf(2)-N(2) bond lengths. Both Hf(2)-O(1) bond lengths are 2.10 Å. In the third Hf site, Hf(3) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form corner-sharing HfN4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. Both Hf(3)-N(1) bond lengths are 2.08 Å. Both Hf(3)-N(2) bond lengths are 2.09 Å. There are two inequivalent N sites. In the first N site, N(2) is bonded to one Hf(3) and three equivalent Hf(2) atoms to form a mixture of distorted corner and edge-sharing NHf4 trigonal pyramids. In the second N site, N(1) is bonded in a distorted rectangular see-saw-like geometry to one Hf(2), one Hf(3), and two equivalent Hf(1) atoms. O(1) is bonded in a distorted trigonal non-coplanar geometry to one Hf(1) and two equivalent Hf(2) atoms.