The crystal structure described by Hf5N5O2 crystallizes in the monoclinic C2/m space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent N(1), three equivalent N(3), and one O(1) atom to form HfN5O octahedra that share  a cornercorner with one Hf(3)N4O2 octahedra, corners with two equivalent Hf(1)N5O octahedra, and edges with five equivalent Hf(1)N5O octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to two equivalent N(3), three equivalent N(2), and two equivalent O(1) atoms. In the third Hf site, Hf(3) is bonded to four equivalent N(2) and two equivalent O(1) atoms to form HfN4O2 octahedra that share corners with two equivalent Hf(1)N5O octahedra and edges with two equivalent Hf(3)N4O2 octahedra. The corner-sharing octahedral tilt angles are 60°. There are three inequivalent N sites. In the first N site, N(1) is bonded in a square co-planar geometry to four equivalent Hf(1) atoms. In the second N site, N(2) is bonded to two equivalent Hf(3) and three equivalent Hf(2) atoms to form distorted NHf5 trigonal bipyramids that share corners with four equivalent O(1)Hf4 tetrahedra, corners with two equivalent N(2)Hf5 trigonal bipyramids, corners with four equivalent N(3)Hf5 trigonal bipyramids, edges with three equivalent O(1)Hf4 tetrahedra,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and edges with five equivalent N(2)Hf5 trigonal bipyramids. In the third N site, N(3) is bonded to two equivalent Hf(2) and three equivalent Hf(1) atoms to form NHf5 trigonal bipyramids that share corners with five equivalent O(1)Hf4 tetrahedra, corners with four equivalent N(2)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 tetrahedra,  an edgeedge with one N(2)Hf5 trigonal bipyramid, and edges with four equivalent N(3)Hf5 trigonal bipyramids. O(1) is bonded to one Hf(1), one Hf(3), and two equivalent Hf(2) atoms to form OHf4 tetrahedra that share corners with three equivalent O(1)Hf4 tetrahedra, corners with four equivalent N(2)Hf5 trigonal bipyramids, corners with five equivalent N(3)Hf5 trigonal bipyramids,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and edges with three equivalent N(2)Hf5 trigonal bipyramids. is represented by the CIF card [CIF]
data_Hf5N5O2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.431
_cell_length_b   5.431
_cell_length_c   9.117
_cell_angle_alpha   75.173
_cell_angle_beta   75.173
_cell_angle_gamma   32.810
_symmetry_Int_Tables_number   1
_cell_volume   140.413
_cell_formula_units_Z   1
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  0.886  0.886  0.423  1.0
  Hf  Hf1  1  0.298  0.298  0.807  1.0
  Hf  Hf2  1  0.702  0.702  0.193  1.0
  Hf  Hf3  1  0.114  0.114  0.577  1.0
  Hf  Hf4  1  0.000  0.000  0.000  1.0
  N  N5  1  0.500  0.500  0.500  1.0
  N  N6  1  0.345  0.345  0.052  1.0
  N  N7  1  0.261  0.261  0.352  1.0
  N  N8  1  0.739  0.739  0.648  1.0
  N  N9  1  0.655  0.655  0.948  1.0
  O  O10  1  0.955  0.955  0.787  1.0
  O  O11  1  0.045  0.045  0.213  1.0
[/CIF]
.
The crystal structure described by Hf5N5O2 crystallizes in the monoclinic C2/m space group. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent N(1), three equivalent N(3), and one O(1) atom to form HfN5O octahedra that share  a cornercorner with one Hf(3)N4O2 octahedra, corners with two equivalent Hf(1)N5O octahedra, and edges with five equivalent Hf(1)N5O octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to two equivalent N(3), three equivalent N(2), and two equivalent O(1) atoms. In the third Hf site, Hf(3) is bonded to four equivalent N(2) and two equivalent O(1) atoms to form HfN4O2 octahedra that share corners with two equivalent Hf(1)N5O octahedra and edges with two equivalent Hf(3)N4O2 octahedra. The corner-sharing octahedral tilt angles are 60°. There are three inequivalent N sites. In the first N site, N(1) is bonded in a square co-planar geometry to four equivalent Hf(1) atoms. In the second N site, N(2) is bonded to two equivalent Hf(3) and three equivalent Hf(2) atoms to form distorted NHf5 trigonal bipyramids that share corners with four equivalent O(1)Hf4 tetrahedra, corners with two equivalent N(2)Hf5 trigonal bipyramids, corners with four equivalent N(3)Hf5 trigonal bipyramids, edges with three equivalent O(1)Hf4 tetrahedra,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and edges with five equivalent N(2)Hf5 trigonal bipyramids. In the third N site, N(3) is bonded to two equivalent Hf(2) and three equivalent Hf(1) atoms to form NHf5 trigonal bipyramids that share corners with five equivalent O(1)Hf4 tetrahedra, corners with four equivalent N(2)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 tetrahedra,  an edgeedge with one N(2)Hf5 trigonal bipyramid, and edges with four equivalent N(3)Hf5 trigonal bipyramids. O(1) is bonded to one Hf(1), one Hf(3), and two equivalent Hf(2) atoms to form OHf4 tetrahedra that share corners with three equivalent O(1)Hf4 tetrahedra, corners with four equivalent N(2)Hf5 trigonal bipyramids, corners with five equivalent N(3)Hf5 trigonal bipyramids,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and edges with three equivalent N(2)Hf5 trigonal bipyramids. is represented by the CIF card [CIF]
data_Hf5N5O2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.431
_cell_length_b   5.431
_cell_length_c   9.117
_cell_angle_alpha   75.173
_cell_angle_beta   75.173
_cell_angle_gamma   32.810
_symmetry_Int_Tables_number   1
_cell_volume   140.413
_cell_formula_units_Z   1
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  0.886  0.886  0.423  1.0
  Hf  Hf1  1  0.298  0.298  0.807  1.0
  Hf  Hf2  1  0.702  0.702  0.193  1.0
  Hf  Hf3  1  0.114  0.114  0.577  1.0
  Hf  Hf4  1  0.000  0.000  0.000  1.0
  N  N5  1  0.500  0.500  0.500  1.0
  N  N6  1  0.345  0.345  0.052  1.0
  N  N7  1  0.261  0.261  0.352  1.0
  N  N8  1  0.739  0.739  0.648  1.0
  N  N9  1  0.655  0.655  0.948  1.0
  O  O10  1  0.955  0.955  0.787  1.0
  O  O11  1  0.045  0.045  0.213  1.0
[/CIF]
.