The material described by Hf2ON2 is Ilmenite-like structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one N(2), one N(3), two equivalent N(1), one O(1), and one O(2) atom to form a mixture of distorted corner, face, and edge-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 43-65°. In the second Hf site, Hf(2) is bonded to one N(2), one N(3), two equivalent N(1), one O(1), and one O(2) atom to form a mixture of distorted corner, face, and edge-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 47-65°. In the third Hf site, Hf(3) is bonded to two equivalent N(2), two equivalent N(3), and two equivalent O(1) atoms to form a mixture of distorted corner, face, and edge-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 43-65°. There are three 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 distorted NHf4 trigonal pyramids that share corners with two equivalent N(1)Hf4 trigonal pyramids, corners with two equivalent N(3)Hf4 trigonal pyramids, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with two equivalent O(2)Hf4 trigonal pyramids,  an edgeedge with one N(1)Hf4 trigonal pyramid,  an edgeedge with one N(3)Hf4 trigonal pyramid,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(2)Hf4 trigonal pyramid. In the second N site, N(2) is bonded in a distorted see-saw-like geometry to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms. In the third N site, N(3) is bonded to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms to form distorted NHf4 trigonal pyramids that share corners with two equivalent N(1)Hf4 trigonal pyramids, corners with two equivalent O(2)Hf4 trigonal pyramids, corners with four equivalent O(1)Hf4 trigonal pyramids,  an edgeedge with one N(1)Hf4 trigonal pyramid,  an edgeedge with one N(3)Hf4 trigonal pyramid, and  an edgeedge with one O(1)Hf4 trigonal pyramid. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms to form distorted OHf4 trigonal pyramids that share corners with two equivalent N(1)Hf4 trigonal pyramids, corners with two equivalent O(2)Hf4 trigonal pyramids, corners with four equivalent N(3)Hf4 trigonal pyramids,  an edgeedge with one N(1)Hf4 trigonal pyramid,  an edgeedge with one N(3)Hf4 trigonal pyramid, and  an edgeedge with one O(1)Hf4 trigonal pyramid. In the second O site, O(2) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form distorted OHf4 trigonal pyramids that share corners with four equivalent N(1)Hf4 trigonal pyramids, corners with four equivalent N(3)Hf4 trigonal pyramids, corners with four equivalent O(1)Hf4 trigonal pyramids, and edges with two equivalent N(1)Hf4 trigonal pyramids. is represented by the CIF file [CIF]
data_Hf2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.480
_cell_length_b   5.480
_cell_length_c   14.612
_cell_angle_alpha   89.938
_cell_angle_beta   89.938
_cell_angle_gamma   59.769
_symmetry_Int_Tables_number   1
_cell_volume   379.136
_cell_formula_units_Z   6
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  0.996  0.000  0.643  1.0
  Hf  Hf1  1  0.000  0.996  0.143  1.0
  Hf  Hf2  1  0.677  0.678  0.810  1.0
  Hf  Hf3  1  0.678  0.674  0.524  1.0
  Hf  Hf4  1  0.678  0.677  0.310  1.0
  Hf  Hf5  1  0.674  0.678  0.024  1.0
  Hf  Hf6  1  0.326  0.322  0.976  1.0
  Hf  Hf7  1  0.322  0.323  0.690  1.0
  Hf  Hf8  1  0.322  0.326  0.476  1.0
  Hf  Hf9  1  0.323  0.322  0.190  1.0
  Hf  Hf10  1  1.000  0.004  0.857  1.0
  Hf  Hf11  1  0.004  1.000  0.357  1.0
  N  N12  1  0.004  0.292  0.752  1.0
  N  N13  1  0.292  0.004  0.252  1.0
  N  N14  1  0.368  0.956  0.918  1.0
  N  N15  1  0.956  0.368  0.418  1.0
  N  N16  1  0.339  0.035  0.585  1.0
  N  N17  1  0.035  0.339  0.085  1.0
  N  N18  1  0.965  0.661  0.915  1.0
  N  N19  1  0.661  0.965  0.415  1.0
  N  N20  1  0.044  0.632  0.582  1.0
  N  N21  1  0.632  0.044  0.082  1.0
  N  N22  1  0.708  0.996  0.748  1.0
  N  N23  1  0.996  0.708  0.248  1.0
  O  O24  1  0.665  0.356  0.918  1.0
  O  O25  1  0.356  0.665  0.418  1.0
  O  O26  1  0.644  0.335  0.582  1.0
  O  O27  1  0.335  0.644  0.082  1.0
  O  O28  1  0.311  0.689  0.750  1.0
  O  O29  1  0.689  0.311  0.250  1.0
[/CIF]
.
The material described by Hf2ON2 is Ilmenite-like structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one N(2), one N(3), two equivalent N(1), one O(1), and one O(2) atom to form a mixture of distorted corner, face, and edge-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 43-65°. In the second Hf site, Hf(2) is bonded to one N(2), one N(3), two equivalent N(1), one O(1), and one O(2) atom to form a mixture of distorted corner, face, and edge-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 47-65°. In the third Hf site, Hf(3) is bonded to two equivalent N(2), two equivalent N(3), and two equivalent O(1) atoms to form a mixture of distorted corner, face, and edge-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 43-65°. There are three 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 distorted NHf4 trigonal pyramids that share corners with two equivalent N(1)Hf4 trigonal pyramids, corners with two equivalent N(3)Hf4 trigonal pyramids, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with two equivalent O(2)Hf4 trigonal pyramids,  an edgeedge with one N(1)Hf4 trigonal pyramid,  an edgeedge with one N(3)Hf4 trigonal pyramid,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(2)Hf4 trigonal pyramid. In the second N site, N(2) is bonded in a distorted see-saw-like geometry to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms. In the third N site, N(3) is bonded to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms to form distorted NHf4 trigonal pyramids that share corners with two equivalent N(1)Hf4 trigonal pyramids, corners with two equivalent O(2)Hf4 trigonal pyramids, corners with four equivalent O(1)Hf4 trigonal pyramids,  an edgeedge with one N(1)Hf4 trigonal pyramid,  an edgeedge with one N(3)Hf4 trigonal pyramid, and  an edgeedge with one O(1)Hf4 trigonal pyramid. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms to form distorted OHf4 trigonal pyramids that share corners with two equivalent N(1)Hf4 trigonal pyramids, corners with two equivalent O(2)Hf4 trigonal pyramids, corners with four equivalent N(3)Hf4 trigonal pyramids,  an edgeedge with one N(1)Hf4 trigonal pyramid,  an edgeedge with one N(3)Hf4 trigonal pyramid, and  an edgeedge with one O(1)Hf4 trigonal pyramid. In the second O site, O(2) is bonded to two equivalent Hf(1) and two equivalent Hf(2) atoms to form distorted OHf4 trigonal pyramids that share corners with four equivalent N(1)Hf4 trigonal pyramids, corners with four equivalent N(3)Hf4 trigonal pyramids, corners with four equivalent O(1)Hf4 trigonal pyramids, and edges with two equivalent N(1)Hf4 trigonal pyramids. is represented by the CIF file [CIF]
data_Hf2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.480
_cell_length_b   5.480
_cell_length_c   14.612
_cell_angle_alpha   89.938
_cell_angle_beta   89.938
_cell_angle_gamma   59.769
_symmetry_Int_Tables_number   1
_cell_volume   379.136
_cell_formula_units_Z   6
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  0.996  0.000  0.643  1.0
  Hf  Hf1  1  0.000  0.996  0.143  1.0
  Hf  Hf2  1  0.677  0.678  0.810  1.0
  Hf  Hf3  1  0.678  0.674  0.524  1.0
  Hf  Hf4  1  0.678  0.677  0.310  1.0
  Hf  Hf5  1  0.674  0.678  0.024  1.0
  Hf  Hf6  1  0.326  0.322  0.976  1.0
  Hf  Hf7  1  0.322  0.323  0.690  1.0
  Hf  Hf8  1  0.322  0.326  0.476  1.0
  Hf  Hf9  1  0.323  0.322  0.190  1.0
  Hf  Hf10  1  1.000  0.004  0.857  1.0
  Hf  Hf11  1  0.004  1.000  0.357  1.0
  N  N12  1  0.004  0.292  0.752  1.0
  N  N13  1  0.292  0.004  0.252  1.0
  N  N14  1  0.368  0.956  0.918  1.0
  N  N15  1  0.956  0.368  0.418  1.0
  N  N16  1  0.339  0.035  0.585  1.0
  N  N17  1  0.035  0.339  0.085  1.0
  N  N18  1  0.965  0.661  0.915  1.0
  N  N19  1  0.661  0.965  0.415  1.0
  N  N20  1  0.044  0.632  0.582  1.0
  N  N21  1  0.632  0.044  0.082  1.0
  N  N22  1  0.708  0.996  0.748  1.0
  N  N23  1  0.996  0.708  0.248  1.0
  O  O24  1  0.665  0.356  0.918  1.0
  O  O25  1  0.356  0.665  0.418  1.0
  O  O26  1  0.644  0.335  0.582  1.0
  O  O27  1  0.335  0.644  0.082  1.0
  O  O28  1  0.311  0.689  0.750  1.0
  O  O29  1  0.689  0.311  0.250  1.0
[/CIF]
.