The crystal structure described by HfO2 is Hydrophilite-like structured and crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the second Hf site, Hf(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form a mixture of edge and corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent Hf(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Hf(1) and two equivalent Hf(2) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Hf(2) and two equivalent Hf(1) atoms. is represented by the CIF card [CIF]
data_HfO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.810
_cell_length_b   5.784
_cell_length_c   15.918
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   442.841
_cell_formula_units_Z   12
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  0.003  0.348  0.084  1.0
  Hf  Hf1  1  0.000  0.023  0.250  1.0
  Hf  Hf2  1  0.997  0.348  0.416  1.0
  Hf  Hf3  1  0.000  0.977  0.750  1.0
  Hf  Hf4  1  0.003  0.652  0.584  1.0
  Hf  Hf5  1  0.997  0.652  0.916  1.0
  Hf  Hf6  1  0.497  0.152  0.584  1.0
  Hf  Hf7  1  0.500  0.523  0.250  1.0
  Hf  Hf8  1  0.503  0.152  0.916  1.0
  Hf  Hf9  1  0.500  0.477  0.750  1.0
  Hf  Hf10  1  0.503  0.848  0.416  1.0
  Hf  Hf11  1  0.497  0.848  0.084  1.0
  O  O12  1  0.204  0.630  0.030  1.0
  O  O13  1  0.204  0.370  0.530  1.0
  O  O14  1  0.279  0.191  0.696  1.0
  O  O15  1  0.279  0.809  0.196  1.0
  O  O16  1  0.212  0.073  0.362  1.0
  O  O17  1  0.212  0.927  0.862  1.0
  O  O18  1  0.288  0.573  0.362  1.0
  O  O19  1  0.288  0.427  0.862  1.0
  O  O20  1  0.221  0.309  0.196  1.0
  O  O21  1  0.221  0.691  0.696  1.0
  O  O22  1  0.296  0.130  0.030  1.0
  O  O23  1  0.296  0.870  0.530  1.0
  O  O24  1  0.704  0.870  0.970  1.0
  O  O25  1  0.704  0.130  0.470  1.0
  O  O26  1  0.779  0.309  0.304  1.0
  O  O27  1  0.779  0.691  0.804  1.0
  O  O28  1  0.712  0.427  0.638  1.0
  O  O29  1  0.712  0.573  0.138  1.0
  O  O30  1  0.788  0.927  0.638  1.0
  O  O31  1  0.788  0.073  0.138  1.0
  O  O32  1  0.721  0.191  0.804  1.0
  O  O33  1  0.721  0.809  0.304  1.0
  O  O34  1  0.796  0.370  0.970  1.0
  O  O35  1  0.796  0.630  0.470  1.0
[/CIF]
.
The crystal structure described by HfO2 is Hydrophilite-like structured and crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the second Hf site, Hf(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form a mixture of edge and corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent Hf(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Hf(1) and two equivalent Hf(2) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Hf(2) and two equivalent Hf(1) atoms. is represented by the CIF card [CIF]
data_HfO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.810
_cell_length_b   5.784
_cell_length_c   15.918
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   442.841
_cell_formula_units_Z   12
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  0.003  0.348  0.084  1.0
  Hf  Hf1  1  0.000  0.023  0.250  1.0
  Hf  Hf2  1  0.997  0.348  0.416  1.0
  Hf  Hf3  1  0.000  0.977  0.750  1.0
  Hf  Hf4  1  0.003  0.652  0.584  1.0
  Hf  Hf5  1  0.997  0.652  0.916  1.0
  Hf  Hf6  1  0.497  0.152  0.584  1.0
  Hf  Hf7  1  0.500  0.523  0.250  1.0
  Hf  Hf8  1  0.503  0.152  0.916  1.0
  Hf  Hf9  1  0.500  0.477  0.750  1.0
  Hf  Hf10  1  0.503  0.848  0.416  1.0
  Hf  Hf11  1  0.497  0.848  0.084  1.0
  O  O12  1  0.204  0.630  0.030  1.0
  O  O13  1  0.204  0.370  0.530  1.0
  O  O14  1  0.279  0.191  0.696  1.0
  O  O15  1  0.279  0.809  0.196  1.0
  O  O16  1  0.212  0.073  0.362  1.0
  O  O17  1  0.212  0.927  0.862  1.0
  O  O18  1  0.288  0.573  0.362  1.0
  O  O19  1  0.288  0.427  0.862  1.0
  O  O20  1  0.221  0.309  0.196  1.0
  O  O21  1  0.221  0.691  0.696  1.0
  O  O22  1  0.296  0.130  0.030  1.0
  O  O23  1  0.296  0.870  0.530  1.0
  O  O24  1  0.704  0.870  0.970  1.0
  O  O25  1  0.704  0.130  0.470  1.0
  O  O26  1  0.779  0.309  0.304  1.0
  O  O27  1  0.779  0.691  0.804  1.0
  O  O28  1  0.712  0.427  0.638  1.0
  O  O29  1  0.712  0.573  0.138  1.0
  O  O30  1  0.788  0.927  0.638  1.0
  O  O31  1  0.788  0.073  0.138  1.0
  O  O32  1  0.721  0.191  0.804  1.0
  O  O33  1  0.721  0.809  0.304  1.0
  O  O34  1  0.796  0.370  0.970  1.0
  O  O35  1  0.796  0.630  0.470  1.0
[/CIF]
.