The structure described by Hf2ON2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 7-coordinate geometry to two equivalent N(2), three equivalent N(1), and two equivalent O(1) atoms. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to two equivalent N(2), three equivalent N(1), and two equivalent O(1) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Hf(1) and three equivalent Hf(2) atoms to form NHf6 octahedra that share corners with six equivalent N(2)Hf4 tetrahedra, corners with six equivalent O(1)Hf4 tetrahedra, edges with six equivalent N(1)Hf6 octahedra, edges with three equivalent N(2)Hf4 tetrahedra, and edges with three equivalent O(1)Hf4 tetrahedra. In the second N site, N(2) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form NHf4 tetrahedra that share corners with six equivalent N(1)Hf6 octahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with four equivalent O(1)Hf4 tetrahedra, edges with three equivalent N(1)Hf6 octahedra,  an edgeedge with one N(2)Hf4 tetrahedra, and edges with two equivalent O(1)Hf4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-57°. O(1) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form distorted OHf4 tetrahedra that share corners with six equivalent N(1)Hf6 octahedra, corners with two equivalent O(1)Hf4 tetrahedra, corners with four equivalent N(2)Hf4 tetrahedra, edges with three equivalent N(1)Hf6 octahedra,  an edgeedge with one O(1)Hf4 tetrahedra, and edges with two equivalent N(2)Hf4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-58°. is represented by the CIF file [CIF]
data_Hf2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.782
_cell_length_b   5.831
_cell_length_c   5.919
_cell_angle_alpha   89.734
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   234.082
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Hf  Hf0  1  0.119  0.746  0.422  1.0
  Hf  Hf1  1  0.133  0.230  0.093  1.0
  Hf  Hf2  1  0.367  0.230  0.593  1.0
  Hf  Hf3  1  0.381  0.746  0.922  1.0
  Hf  Hf4  1  0.633  0.770  0.407  1.0
  Hf  Hf5  1  0.619  0.254  0.078  1.0
  Hf  Hf6  1  0.881  0.254  0.578  1.0
  Hf  Hf7  1  0.867  0.770  0.907  1.0
  N  N8  1  0.127  0.996  0.741  1.0
  N  N9  1  0.133  0.368  0.413  1.0
  N  N10  1  0.373  0.996  0.241  1.0
  N  N11  1  0.367  0.368  0.913  1.0
  N  N12  1  0.627  0.004  0.759  1.0
  N  N13  1  0.633  0.632  0.087  1.0
  N  N14  1  0.867  0.632  0.587  1.0
  N  N15  1  0.873  0.004  0.259  1.0
  O  O16  1  0.117  0.653  0.081  1.0
  O  O17  1  0.383  0.653  0.581  1.0
  O  O18  1  0.617  0.347  0.419  1.0
  O  O19  1  0.883  0.347  0.919  1.0
[/CIF]
.
The structure described by Hf2ON2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 7-coordinate geometry to two equivalent N(2), three equivalent N(1), and two equivalent O(1) atoms. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to two equivalent N(2), three equivalent N(1), and two equivalent O(1) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Hf(1) and three equivalent Hf(2) atoms to form NHf6 octahedra that share corners with six equivalent N(2)Hf4 tetrahedra, corners with six equivalent O(1)Hf4 tetrahedra, edges with six equivalent N(1)Hf6 octahedra, edges with three equivalent N(2)Hf4 tetrahedra, and edges with three equivalent O(1)Hf4 tetrahedra. In the second N site, N(2) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form NHf4 tetrahedra that share corners with six equivalent N(1)Hf6 octahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with four equivalent O(1)Hf4 tetrahedra, edges with three equivalent N(1)Hf6 octahedra,  an edgeedge with one N(2)Hf4 tetrahedra, and edges with two equivalent O(1)Hf4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-57°. O(1) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form distorted OHf4 tetrahedra that share corners with six equivalent N(1)Hf6 octahedra, corners with two equivalent O(1)Hf4 tetrahedra, corners with four equivalent N(2)Hf4 tetrahedra, edges with three equivalent N(1)Hf6 octahedra,  an edgeedge with one O(1)Hf4 tetrahedra, and edges with two equivalent N(2)Hf4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-58°. is represented by the CIF file [CIF]
data_Hf2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.782
_cell_length_b   5.831
_cell_length_c   5.919
_cell_angle_alpha   89.734
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   234.082
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Hf  Hf0  1  0.119  0.746  0.422  1.0
  Hf  Hf1  1  0.133  0.230  0.093  1.0
  Hf  Hf2  1  0.367  0.230  0.593  1.0
  Hf  Hf3  1  0.381  0.746  0.922  1.0
  Hf  Hf4  1  0.633  0.770  0.407  1.0
  Hf  Hf5  1  0.619  0.254  0.078  1.0
  Hf  Hf6  1  0.881  0.254  0.578  1.0
  Hf  Hf7  1  0.867  0.770  0.907  1.0
  N  N8  1  0.127  0.996  0.741  1.0
  N  N9  1  0.133  0.368  0.413  1.0
  N  N10  1  0.373  0.996  0.241  1.0
  N  N11  1  0.367  0.368  0.913  1.0
  N  N12  1  0.627  0.004  0.759  1.0
  N  N13  1  0.633  0.632  0.087  1.0
  N  N14  1  0.867  0.632  0.587  1.0
  N  N15  1  0.873  0.004  0.259  1.0
  O  O16  1  0.117  0.653  0.081  1.0
  O  O17  1  0.383  0.653  0.581  1.0
  O  O18  1  0.617  0.347  0.419  1.0
  O  O19  1  0.883  0.347  0.919  1.0
[/CIF]
.