The material structure described by Hf2ON2 crystallizes in the monoclinic Pm space group. There are twelve inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 7-coordinate geometry to one N(1), one N(10), one N(11), two equivalent O(1), and two equivalent O(3) atoms. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to one N(1), one N(12), one N(2), two equivalent O(1), and two equivalent O(2) atoms. In the third Hf site, Hf(3) is bonded to one N(4), two equivalent N(1), two equivalent N(3), and one O(3) atom to form HfN5O octahedra that share corners with two equivalent Hf(4)N4O2 octahedra,  an edgeedge with one Hf(4)N4O2 octahedra, and edges with two equivalent Hf(3)N5O octahedra. The corner-sharing octahedral tilt angles are 9°. In the fourth Hf site, Hf(4) is bonded to two equivalent N(2), two equivalent N(3), one O(2), and one O(4) atom to form HfN4O2 octahedra that share corners with two equivalent Hf(3)N5O octahedra,  an edgeedge with one Hf(3)N5O octahedra, and edges with two equivalent Hf(4)N4O2 octahedra. The corner-sharing octahedral tilt angles are 9°. In the fifth Hf site, Hf(5) is bonded in a 6-coordinate geometry to one N(2), one N(5), two equivalent N(4), and two equivalent O(5) atoms. In the sixth Hf site, Hf(6) is bonded in a 7-coordinate geometry to one N(3), one N(5), one N(6), two equivalent N(4), and two equivalent O(4) atoms. In the seventh Hf site, Hf(7) is bonded in a 7-coordinate geometry to one N(7), two equivalent N(6), one O(4), one O(5), and two equivalent O(6) atoms. In the eighth Hf site, Hf(8) is bonded in a 7-coordinate geometry to one N(8), one N(9), two equivalent N(5), one O(5), and two equivalent O(6) atoms. In the ninth Hf site, Hf(9) is bonded to one N(11), one N(6), two equivalent N(7), and two equivalent N(8) atoms to form HfN6 octahedra that share corners with two equivalent Hf(10)N5O octahedra,  an edgeedge with one Hf(10)N5O octahedra, and edges with two equivalent Hf(9)N6 octahedra. The corner-sharing octahedral tilt angles are 17°. In the tenth Hf site, Hf(10) is bonded to one N(10), two equivalent N(7), two equivalent N(9), and one O(6) atom to form HfN5O octahedra that share corners with two equivalent Hf(9)N6 octahedra,  an edgeedge with one Hf(9)N6 octahedra, and edges with two equivalent Hf(10)N5O octahedra. The corner-sharing octahedral tilt angles are 17°. In the eleventh Hf site, Hf(11) is bonded in a 7-coordinate geometry to one N(8), one N(9), two equivalent N(11), two equivalent N(12), and one O(1) atom. In the twelfth Hf site, Hf(12) is bonded in a 7-coordinate geometry to one N(9), two equivalent N(10), two equivalent N(12), one O(2), and one O(3) atom. There are twelve inequivalent N sites. In the first N site, N(1) is bonded in a 4-coordinate geometry to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms. In the second N site, N(2) is bonded to one Hf(2), one Hf(5), and two equivalent Hf(4) atoms to form distorted NHf4 tetrahedra that share corners with two equivalent N(3)Hf5 square pyramids, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra,  a cornercorner with one N(12)Hf5 trigonal bipyramid, corners with two equivalent N(4)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf5 trigonal bipyramids,  a cornercorner with one N(5)Hf4 trigonal pyramid, corners with two equivalent O(5)Hf4 trigonal pyramids,  an edgeedge with one N(3)Hf5 square pyramid, and edges with two equivalent O(2)Hf4 tetrahedra. In the third N site, N(3) is bonded to one Hf(6), two equivalent Hf(3), and two equivalent Hf(4) atoms to form NHf5 square pyramids that share  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  a cornercorner with one N(5)Hf4 trigonal pyramid, edges with two equivalent N(3)Hf5 square pyramids,  an edgeedge with one N(2)Hf4 tetrahedra, edges with two equivalent O(4)Hf4 tetrahedra, and edges with two equivalent N(4)Hf5 trigonal bipyramids. In the fourth N site, N(4) is bonded to one Hf(3), two equivalent Hf(5), and two equivalent Hf(6) atoms to form distorted NHf5 trigonal bipyramids that share  a cornercorner with one O(3)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent O(5)Hf4 trigonal pyramids, edges with two equivalent N(3)Hf5 square pyramids,  an edgeedge with one O(4)Hf4 tetrahedra, edges with two equivalent N(4)Hf5 trigonal bipyramids,  an edgeedge with one O(5)Hf4 trigonal pyramid, and edges with two equivalent N(5)Hf4 trigonal pyramids. In the fifth N site, N(5) is bonded to one Hf(5), one Hf(6), and two equivalent Hf(8) atoms to form distorted NHf4 trigonal pyramids that share  a cornercorner with one N(3)Hf5 square pyramid, corners with two equivalent O(6)Hf5 square pyramids,  a cornercorner with one N(2)Hf4 tetrahedra,  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent N(9)Hf5 trigonal bipyramids, corners with two equivalent N(5)Hf4 trigonal pyramids,  an edgeedge with one O(6)Hf5 square pyramid, edges with two equivalent N(4)Hf5 trigonal bipyramids, and edges with two equivalent O(5)Hf4 trigonal pyramids. In the sixth N site, N(6) is bonded to one Hf(6), one Hf(9), and two equivalent Hf(7) atoms to form NHf4 tetrahedra that share  a cornercorner with one N(3)Hf5 square pyramid, corners with two equivalent O(6)Hf5 square pyramids,  a cornercorner with one N(11)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent N(4)Hf5 trigonal bipyramids,  a cornercorner with one N(5)Hf4 trigonal pyramid, corners with two equivalent O(5)Hf4 trigonal pyramids,  an edgeedge with one O(6)Hf5 square pyramid, edges with two equivalent N(7)Hf5 square pyramids, and edges with two equivalent O(4)Hf4 tetrahedra. In the seventh N site, N(7) is bonded to one Hf(7), two equivalent Hf(10), and two equivalent Hf(9) atoms to form NHf5 square pyramids that share  a cornercorner with one O(4)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent N(9)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, edges with two equivalent N(7)Hf5 square pyramids, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(8)Hf4 tetrahedra, edges with two equivalent N(6)Hf4 tetrahedra, and  an edgeedge with one N(9)Hf5 trigonal bipyramid. In the eighth N site, N(8) is bonded to one Hf(11), one Hf(8), and two equivalent Hf(9) atoms to form distorted NHf4 tetrahedra that share corners with two equivalent N(7)Hf5 square pyramids, corners with two equivalent O(6)Hf5 square pyramids, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra,  a cornercorner with one O(1)Hf5 trigonal bipyramid, corners with two equivalent N(12)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, corners with two equivalent N(5)Hf4 trigonal pyramids,  an edgeedge with one N(7)Hf5 square pyramid, edges with two equivalent N(11)Hf4 tetrahedra, and  an edgeedge with one N(9)Hf5 trigonal bipyramid. In the ninth N site, N(9) is bonded to one Hf(11), one Hf(12), one Hf(8), and two equivalent Hf(10) atoms to form distorted NHf5 trigonal bipyramids that share corners with two equivalent N(7)Hf5 square pyramids,  a cornercorner with one O(2)Hf4 tetrahedra,  a cornercorner with one O(3)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra,  a cornercorner with one O(1)Hf5 trigonal bipyramid, corners with two equivalent N(9)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, corners with two equivalent N(5)Hf4 trigonal pyramids,  an edgeedge with one N(7)Hf5 square pyramid, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(8)Hf4 tetrahedra, edges with two equivalent N(10)Hf4 tetrahedra, and edges with two equivalent N(12)Hf5 trigonal bipyramids. In the tenth N site, N(10) is bonded to one Hf(1), one Hf(10), and two equivalent Hf(12) atoms to form NHf4 tetrahedra that share  a cornercorner with one O(6)Hf5 square pyramid, corners with two equivalent N(7)Hf5 square pyramids,  a cornercorner with one N(11)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent N(12)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf5 trigonal bipyramids, edges with two equivalent O(3)Hf4 tetrahedra,  an edgeedge with one N(12)Hf5 trigonal bipyramid, and edges with two equivalent N(9)Hf5 trigonal bipyramids. In the eleventh N site, N(11) is bonded to one Hf(1), one Hf(9), and two equivalent Hf(11) atoms to form NHf4 tetrahedra that share corners with two equivalent N(7)Hf5 square pyramids,  a cornercorner with one N(10)Hf4 tetrahedra,  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra, corners with two equivalent N(12)Hf5 trigonal bipyramids, corners with two equivalent N(9)Hf5 trigonal bipyramids, edges with two equivalent N(8)Hf4 tetrahedra,  an edgeedge with one N(12)Hf5 trigonal bipyramid, and edges with two equivalent O(1)Hf5 trigonal bipyramids. In the twelfth N site, N(12) is bonded to one Hf(2), two equivalent Hf(11), and two equivalent Hf(12) atoms to form distorted NHf5 trigonal bipyramids that share  a cornercorner with one N(2)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  an edgeedge with one N(10)Hf4 tetrahedra,  an edgeedge with one N(11)Hf4 tetrahedra, edges with two equivalent O(2)Hf4 tetrahedra, edges with two equivalent N(12)Hf5 trigonal bipyramids, edges with two equivalent N(9)Hf5 trigonal bipyramids, and edges with two equivalent O(1)Hf5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Hf(11), two equivalent Hf(1), and two equivalent Hf(2) atoms to form OHf5 trigonal bipyramids that share  a cornercorner with one N(8)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  a cornercorner with one N(9)Hf5 trigonal bipyramid,  an edgeedge with one O(2)Hf4 tetrahedra,  an edgeedge with one O(3)Hf4 tetrahedra, edges with two equivalent N(11)Hf4 tetrahedra, edges with two equivalent N(12)Hf5 trigonal bipyramids, and edges with two equivalent O(1)Hf5 trigonal bipyramids. In the second O site, O(2) is bonded to one Hf(12), one Hf(4), and two equivalent Hf(2) atoms to form OHf4 tetrahedra that share corners with two equivalent N(3)Hf5 square pyramids,  a cornercorner with one O(3)Hf4 tetrahedra,  a cornercorner with one O(4)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(9)Hf5 trigonal bipyramid, corners with two equivalent O(1)Hf5 trigonal bipyramids, edges with two equivalent N(2)Hf4 tetrahedra,  an edgeedge with one O(1)Hf5 trigonal bipyramid, and edges with two equivalent N(12)Hf5 trigonal bipyramids. In the third O site, O(3) is bonded to one Hf(12), one Hf(3), and two equivalent Hf(1) atoms to form distorted OHf4 tetrahedra that share corners with two equivalent N(3)Hf5 square pyramids,  a cornercorner with one O(2)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  a cornercorner with one N(4)Hf5 trigonal bipyramid,  a cornercorner with one N(9)Hf5 trigonal bipyramid, corners with two equivalent N(12)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf5 trigonal bipyramids, edges with two equivalent N(10)Hf4 tetrahedra, and  an edgeedge with one O(1)Hf5 trigonal bipyramid. In the fourth O site, O(4) is bonded to one Hf(4), one Hf(7), and two equivalent Hf(6) atoms to form OHf4 tetrahedra that share  a cornercorner with one N(7)Hf5 square pyramid, corners with two equivalent O(6)Hf5 square pyramids,  a cornercorner with one O(2)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent N(4)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, corners with two equivalent N(5)Hf4 trigonal pyramids, edges with two equivalent N(3)Hf5 square pyramids, edges with two equivalent N(6)Hf4 tetrahedra, and  an edgeedge with one N(4)Hf5 trigonal bipyramid. In the fifth O site, O(5) is bonded to one Hf(7), one Hf(8), and two equivalent Hf(5) atoms to form distorted OHf4 trigonal pyramids that share  a cornercorner with one N(7)Hf5 square pyramid,  a cornercorner with one N(8)Hf4 tetrahedra,  a cornercorner with one O(4)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra,  a cornercorner with one N(9)Hf5 trigonal bipyramid, corners with two equivalent N(4)Hf5 trigonal bipyramids, corners with two equivalent O(5)Hf4 trigonal pyramids, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(4)Hf5 trigonal bipyramid, and edges with two equivalent N(5)Hf4 trigonal pyramids. In the sixth O site, O(6) is bonded to one Hf(10), two equivalent Hf(7), and two equivalent Hf(8) atoms to form distorted OHf5 square pyramids that share  a cornercorner with one N(10)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent N(5)Hf4 trigonal pyramids, edges with two equivalent N(7)Hf5 square pyramids, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(6)Hf4 tetrahedra, edges with two equivalent N(9)Hf5 trigonal bipyramids,  an edgeedge with one N(5)Hf4 trigonal pyramid, and edges with two equivalent O(5)Hf4 trigonal pyramids. is represented by the CIF card [CIF]
data_Hf2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.276
_cell_length_b   8.121
_cell_length_c   13.757
_cell_angle_alpha   80.493
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   361.026
_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  0.500  0.822  0.008  1.0
  Hf  Hf1  1  0.500  0.453  0.120  1.0
  Hf  Hf2  1  0.000  0.810  0.223  1.0
  Hf  Hf3  1  0.000  0.170  0.283  1.0
  Hf  Hf4  1  0.500  0.501  0.391  1.0
  Hf  Hf5  1  0.500  0.855  0.438  1.0
  Hf  Hf6  1  0.000  0.120  0.570  1.0
  Hf  Hf7  1  0.000  0.505  0.616  1.0
  Hf  Hf8  1  0.500  0.827  0.719  1.0
  Hf  Hf9  1  0.500  0.185  0.782  1.0
  Hf  Hf10  1  0.000  0.555  0.879  1.0
  Hf  Hf11  1  0.000  0.195  0.983  1.0
  N  N12  1  0.500  0.676  0.181  1.0
  N  N13  1  0.500  0.337  0.285  1.0
  N  N14  1  0.500  0.982  0.266  1.0
  N  N15  1  0.000  0.691  0.371  1.0
  N  N16  1  0.500  0.618  0.535  1.0
  N  N17  1  0.500  0.966  0.568  1.0
  N  N18  1  0.000  0.025  0.727  1.0
  N  N19  1  0.000  0.664  0.716  1.0
  N  N20  1  0.000  0.334  0.810  1.0
  N  N21  1  0.500  0.065  0.929  1.0
  N  N22  1  0.500  0.730  0.874  1.0
  N  N23  1  0.500  0.387  0.974  1.0
  O  O24  1  0.000  0.622  0.034  1.0
  O  O25  1  0.000  0.281  0.130  1.0
  O  O26  1  0.000  0.940  0.071  1.0
  O  O27  1  0.000  0.026  0.424  1.0
  O  O28  1  0.000  0.359  0.466  1.0
  O  O29  1  0.500  0.299  0.627  1.0
[/CIF]
.
The material structure described by Hf2ON2 crystallizes in the monoclinic Pm space group. There are twelve inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 7-coordinate geometry to one N(1), one N(10), one N(11), two equivalent O(1), and two equivalent O(3) atoms. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to one N(1), one N(12), one N(2), two equivalent O(1), and two equivalent O(2) atoms. In the third Hf site, Hf(3) is bonded to one N(4), two equivalent N(1), two equivalent N(3), and one O(3) atom to form HfN5O octahedra that share corners with two equivalent Hf(4)N4O2 octahedra,  an edgeedge with one Hf(4)N4O2 octahedra, and edges with two equivalent Hf(3)N5O octahedra. The corner-sharing octahedral tilt angles are 9°. In the fourth Hf site, Hf(4) is bonded to two equivalent N(2), two equivalent N(3), one O(2), and one O(4) atom to form HfN4O2 octahedra that share corners with two equivalent Hf(3)N5O octahedra,  an edgeedge with one Hf(3)N5O octahedra, and edges with two equivalent Hf(4)N4O2 octahedra. The corner-sharing octahedral tilt angles are 9°. In the fifth Hf site, Hf(5) is bonded in a 6-coordinate geometry to one N(2), one N(5), two equivalent N(4), and two equivalent O(5) atoms. In the sixth Hf site, Hf(6) is bonded in a 7-coordinate geometry to one N(3), one N(5), one N(6), two equivalent N(4), and two equivalent O(4) atoms. In the seventh Hf site, Hf(7) is bonded in a 7-coordinate geometry to one N(7), two equivalent N(6), one O(4), one O(5), and two equivalent O(6) atoms. In the eighth Hf site, Hf(8) is bonded in a 7-coordinate geometry to one N(8), one N(9), two equivalent N(5), one O(5), and two equivalent O(6) atoms. In the ninth Hf site, Hf(9) is bonded to one N(11), one N(6), two equivalent N(7), and two equivalent N(8) atoms to form HfN6 octahedra that share corners with two equivalent Hf(10)N5O octahedra,  an edgeedge with one Hf(10)N5O octahedra, and edges with two equivalent Hf(9)N6 octahedra. The corner-sharing octahedral tilt angles are 17°. In the tenth Hf site, Hf(10) is bonded to one N(10), two equivalent N(7), two equivalent N(9), and one O(6) atom to form HfN5O octahedra that share corners with two equivalent Hf(9)N6 octahedra,  an edgeedge with one Hf(9)N6 octahedra, and edges with two equivalent Hf(10)N5O octahedra. The corner-sharing octahedral tilt angles are 17°. In the eleventh Hf site, Hf(11) is bonded in a 7-coordinate geometry to one N(8), one N(9), two equivalent N(11), two equivalent N(12), and one O(1) atom. In the twelfth Hf site, Hf(12) is bonded in a 7-coordinate geometry to one N(9), two equivalent N(10), two equivalent N(12), one O(2), and one O(3) atom. There are twelve inequivalent N sites. In the first N site, N(1) is bonded in a 4-coordinate geometry to one Hf(1), one Hf(2), and two equivalent Hf(3) atoms. In the second N site, N(2) is bonded to one Hf(2), one Hf(5), and two equivalent Hf(4) atoms to form distorted NHf4 tetrahedra that share corners with two equivalent N(3)Hf5 square pyramids, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra,  a cornercorner with one N(12)Hf5 trigonal bipyramid, corners with two equivalent N(4)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf5 trigonal bipyramids,  a cornercorner with one N(5)Hf4 trigonal pyramid, corners with two equivalent O(5)Hf4 trigonal pyramids,  an edgeedge with one N(3)Hf5 square pyramid, and edges with two equivalent O(2)Hf4 tetrahedra. In the third N site, N(3) is bonded to one Hf(6), two equivalent Hf(3), and two equivalent Hf(4) atoms to form NHf5 square pyramids that share  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  a cornercorner with one N(5)Hf4 trigonal pyramid, edges with two equivalent N(3)Hf5 square pyramids,  an edgeedge with one N(2)Hf4 tetrahedra, edges with two equivalent O(4)Hf4 tetrahedra, and edges with two equivalent N(4)Hf5 trigonal bipyramids. In the fourth N site, N(4) is bonded to one Hf(3), two equivalent Hf(5), and two equivalent Hf(6) atoms to form distorted NHf5 trigonal bipyramids that share  a cornercorner with one O(3)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent O(5)Hf4 trigonal pyramids, edges with two equivalent N(3)Hf5 square pyramids,  an edgeedge with one O(4)Hf4 tetrahedra, edges with two equivalent N(4)Hf5 trigonal bipyramids,  an edgeedge with one O(5)Hf4 trigonal pyramid, and edges with two equivalent N(5)Hf4 trigonal pyramids. In the fifth N site, N(5) is bonded to one Hf(5), one Hf(6), and two equivalent Hf(8) atoms to form distorted NHf4 trigonal pyramids that share  a cornercorner with one N(3)Hf5 square pyramid, corners with two equivalent O(6)Hf5 square pyramids,  a cornercorner with one N(2)Hf4 tetrahedra,  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent N(9)Hf5 trigonal bipyramids, corners with two equivalent N(5)Hf4 trigonal pyramids,  an edgeedge with one O(6)Hf5 square pyramid, edges with two equivalent N(4)Hf5 trigonal bipyramids, and edges with two equivalent O(5)Hf4 trigonal pyramids. In the sixth N site, N(6) is bonded to one Hf(6), one Hf(9), and two equivalent Hf(7) atoms to form NHf4 tetrahedra that share  a cornercorner with one N(3)Hf5 square pyramid, corners with two equivalent O(6)Hf5 square pyramids,  a cornercorner with one N(11)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent N(4)Hf5 trigonal bipyramids,  a cornercorner with one N(5)Hf4 trigonal pyramid, corners with two equivalent O(5)Hf4 trigonal pyramids,  an edgeedge with one O(6)Hf5 square pyramid, edges with two equivalent N(7)Hf5 square pyramids, and edges with two equivalent O(4)Hf4 tetrahedra. In the seventh N site, N(7) is bonded to one Hf(7), two equivalent Hf(10), and two equivalent Hf(9) atoms to form NHf5 square pyramids that share  a cornercorner with one O(4)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent N(9)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, edges with two equivalent N(7)Hf5 square pyramids, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(8)Hf4 tetrahedra, edges with two equivalent N(6)Hf4 tetrahedra, and  an edgeedge with one N(9)Hf5 trigonal bipyramid. In the eighth N site, N(8) is bonded to one Hf(11), one Hf(8), and two equivalent Hf(9) atoms to form distorted NHf4 tetrahedra that share corners with two equivalent N(7)Hf5 square pyramids, corners with two equivalent O(6)Hf5 square pyramids, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra,  a cornercorner with one O(1)Hf5 trigonal bipyramid, corners with two equivalent N(12)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, corners with two equivalent N(5)Hf4 trigonal pyramids,  an edgeedge with one N(7)Hf5 square pyramid, edges with two equivalent N(11)Hf4 tetrahedra, and  an edgeedge with one N(9)Hf5 trigonal bipyramid. In the ninth N site, N(9) is bonded to one Hf(11), one Hf(12), one Hf(8), and two equivalent Hf(10) atoms to form distorted NHf5 trigonal bipyramids that share corners with two equivalent N(7)Hf5 square pyramids,  a cornercorner with one O(2)Hf4 tetrahedra,  a cornercorner with one O(3)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra,  a cornercorner with one O(1)Hf5 trigonal bipyramid, corners with two equivalent N(9)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, corners with two equivalent N(5)Hf4 trigonal pyramids,  an edgeedge with one N(7)Hf5 square pyramid, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(8)Hf4 tetrahedra, edges with two equivalent N(10)Hf4 tetrahedra, and edges with two equivalent N(12)Hf5 trigonal bipyramids. In the tenth N site, N(10) is bonded to one Hf(1), one Hf(10), and two equivalent Hf(12) atoms to form NHf4 tetrahedra that share  a cornercorner with one O(6)Hf5 square pyramid, corners with two equivalent N(7)Hf5 square pyramids,  a cornercorner with one N(11)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent N(12)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf5 trigonal bipyramids, edges with two equivalent O(3)Hf4 tetrahedra,  an edgeedge with one N(12)Hf5 trigonal bipyramid, and edges with two equivalent N(9)Hf5 trigonal bipyramids. In the eleventh N site, N(11) is bonded to one Hf(1), one Hf(9), and two equivalent Hf(11) atoms to form NHf4 tetrahedra that share corners with two equivalent N(7)Hf5 square pyramids,  a cornercorner with one N(10)Hf4 tetrahedra,  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra, corners with two equivalent N(12)Hf5 trigonal bipyramids, corners with two equivalent N(9)Hf5 trigonal bipyramids, edges with two equivalent N(8)Hf4 tetrahedra,  an edgeedge with one N(12)Hf5 trigonal bipyramid, and edges with two equivalent O(1)Hf5 trigonal bipyramids. In the twelfth N site, N(12) is bonded to one Hf(2), two equivalent Hf(11), and two equivalent Hf(12) atoms to form distorted NHf5 trigonal bipyramids that share  a cornercorner with one N(2)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  an edgeedge with one N(10)Hf4 tetrahedra,  an edgeedge with one N(11)Hf4 tetrahedra, edges with two equivalent O(2)Hf4 tetrahedra, edges with two equivalent N(12)Hf5 trigonal bipyramids, edges with two equivalent N(9)Hf5 trigonal bipyramids, and edges with two equivalent O(1)Hf5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Hf(11), two equivalent Hf(1), and two equivalent Hf(2) atoms to form OHf5 trigonal bipyramids that share  a cornercorner with one N(8)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  a cornercorner with one N(9)Hf5 trigonal bipyramid,  an edgeedge with one O(2)Hf4 tetrahedra,  an edgeedge with one O(3)Hf4 tetrahedra, edges with two equivalent N(11)Hf4 tetrahedra, edges with two equivalent N(12)Hf5 trigonal bipyramids, and edges with two equivalent O(1)Hf5 trigonal bipyramids. In the second O site, O(2) is bonded to one Hf(12), one Hf(4), and two equivalent Hf(2) atoms to form OHf4 tetrahedra that share corners with two equivalent N(3)Hf5 square pyramids,  a cornercorner with one O(3)Hf4 tetrahedra,  a cornercorner with one O(4)Hf4 tetrahedra, corners with two equivalent N(10)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(9)Hf5 trigonal bipyramid, corners with two equivalent O(1)Hf5 trigonal bipyramids, edges with two equivalent N(2)Hf4 tetrahedra,  an edgeedge with one O(1)Hf5 trigonal bipyramid, and edges with two equivalent N(12)Hf5 trigonal bipyramids. In the third O site, O(3) is bonded to one Hf(12), one Hf(3), and two equivalent Hf(1) atoms to form distorted OHf4 tetrahedra that share corners with two equivalent N(3)Hf5 square pyramids,  a cornercorner with one O(2)Hf4 tetrahedra, corners with two equivalent N(11)Hf4 tetrahedra, corners with two equivalent O(3)Hf4 tetrahedra,  a cornercorner with one N(4)Hf5 trigonal bipyramid,  a cornercorner with one N(9)Hf5 trigonal bipyramid, corners with two equivalent N(12)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf5 trigonal bipyramids, edges with two equivalent N(10)Hf4 tetrahedra, and  an edgeedge with one O(1)Hf5 trigonal bipyramid. In the fourth O site, O(4) is bonded to one Hf(4), one Hf(7), and two equivalent Hf(6) atoms to form OHf4 tetrahedra that share  a cornercorner with one N(7)Hf5 square pyramid, corners with two equivalent O(6)Hf5 square pyramids,  a cornercorner with one O(2)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent N(4)Hf5 trigonal bipyramids,  a cornercorner with one O(5)Hf4 trigonal pyramid, corners with two equivalent N(5)Hf4 trigonal pyramids, edges with two equivalent N(3)Hf5 square pyramids, edges with two equivalent N(6)Hf4 tetrahedra, and  an edgeedge with one N(4)Hf5 trigonal bipyramid. In the fifth O site, O(5) is bonded to one Hf(7), one Hf(8), and two equivalent Hf(5) atoms to form distorted OHf4 trigonal pyramids that share  a cornercorner with one N(7)Hf5 square pyramid,  a cornercorner with one N(8)Hf4 tetrahedra,  a cornercorner with one O(4)Hf4 tetrahedra, corners with two equivalent N(2)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra,  a cornercorner with one N(9)Hf5 trigonal bipyramid, corners with two equivalent N(4)Hf5 trigonal bipyramids, corners with two equivalent O(5)Hf4 trigonal pyramids, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(4)Hf5 trigonal bipyramid, and edges with two equivalent N(5)Hf4 trigonal pyramids. In the sixth O site, O(6) is bonded to one Hf(10), two equivalent Hf(7), and two equivalent Hf(8) atoms to form distorted OHf5 square pyramids that share  a cornercorner with one N(10)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(4)Hf4 tetrahedra, corners with two equivalent N(5)Hf4 trigonal pyramids, edges with two equivalent N(7)Hf5 square pyramids, edges with two equivalent O(6)Hf5 square pyramids,  an edgeedge with one N(6)Hf4 tetrahedra, edges with two equivalent N(9)Hf5 trigonal bipyramids,  an edgeedge with one N(5)Hf4 trigonal pyramid, and edges with two equivalent O(5)Hf4 trigonal pyramids. is represented by the CIF card [CIF]
data_Hf2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.276
_cell_length_b   8.121
_cell_length_c   13.757
_cell_angle_alpha   80.493
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   361.026
_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  0.500  0.822  0.008  1.0
  Hf  Hf1  1  0.500  0.453  0.120  1.0
  Hf  Hf2  1  0.000  0.810  0.223  1.0
  Hf  Hf3  1  0.000  0.170  0.283  1.0
  Hf  Hf4  1  0.500  0.501  0.391  1.0
  Hf  Hf5  1  0.500  0.855  0.438  1.0
  Hf  Hf6  1  0.000  0.120  0.570  1.0
  Hf  Hf7  1  0.000  0.505  0.616  1.0
  Hf  Hf8  1  0.500  0.827  0.719  1.0
  Hf  Hf9  1  0.500  0.185  0.782  1.0
  Hf  Hf10  1  0.000  0.555  0.879  1.0
  Hf  Hf11  1  0.000  0.195  0.983  1.0
  N  N12  1  0.500  0.676  0.181  1.0
  N  N13  1  0.500  0.337  0.285  1.0
  N  N14  1  0.500  0.982  0.266  1.0
  N  N15  1  0.000  0.691  0.371  1.0
  N  N16  1  0.500  0.618  0.535  1.0
  N  N17  1  0.500  0.966  0.568  1.0
  N  N18  1  0.000  0.025  0.727  1.0
  N  N19  1  0.000  0.664  0.716  1.0
  N  N20  1  0.000  0.334  0.810  1.0
  N  N21  1  0.500  0.065  0.929  1.0
  N  N22  1  0.500  0.730  0.874  1.0
  N  N23  1  0.500  0.387  0.974  1.0
  O  O24  1  0.000  0.622  0.034  1.0
  O  O25  1  0.000  0.281  0.130  1.0
  O  O26  1  0.000  0.940  0.071  1.0
  O  O27  1  0.000  0.026  0.424  1.0
  O  O28  1  0.000  0.359  0.466  1.0
  O  O29  1  0.500  0.299  0.627  1.0
[/CIF]
.