The crystal structure described by HfO2 is Baddeleyite-like structured and crystallizes in the orthorhombic P2_12_12 space group. Hf(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to three equivalent Hf(1) atoms. In the second O site, O(1) is bonded to four equivalent Hf(1) atoms to form a mixture of distorted corner and edge-sharing OHf4 trigonal pyramids. In the third O site, O(2) is bonded to four equivalent Hf(1) atoms to form a mixture of corner and edge-sharing OHf4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.891
_cell_length_b   5.080
_cell_length_c   5.165
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   128.333
_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  0.728  0.277  0.282  1.0
  Hf  Hf1  1  0.272  0.777  0.218  1.0
  Hf  Hf2  1  0.728  0.723  0.718  1.0
  Hf  Hf3  1  0.272  0.223  0.782  1.0
  O  O4  1  0.424  0.500  0.500  1.0
  O  O5  1  0.576  0.000  0.000  1.0
  O  O6  1  0.511  0.500  0.000  1.0
  O  O7  1  0.489  0.000  0.500  1.0
  O  O8  1  0.895  0.313  0.664  1.0
  O  O9  1  0.105  0.813  0.836  1.0
  O  O10  1  0.895  0.687  0.336  1.0
  O  O11  1  0.105  0.187  0.164  1.0
[/CIF]
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The crystal structure described by HfO2 is Baddeleyite-like structured and crystallizes in the orthorhombic P2_12_12 space group. Hf(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to three equivalent Hf(1) atoms. In the second O site, O(1) is bonded to four equivalent Hf(1) atoms to form a mixture of distorted corner and edge-sharing OHf4 trigonal pyramids. In the third O site, O(2) is bonded to four equivalent Hf(1) atoms to form a mixture of corner and edge-sharing OHf4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.891
_cell_length_b   5.080
_cell_length_c   5.165
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   128.333
_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  0.728  0.277  0.282  1.0
  Hf  Hf1  1  0.272  0.777  0.218  1.0
  Hf  Hf2  1  0.728  0.723  0.718  1.0
  Hf  Hf3  1  0.272  0.223  0.782  1.0
  O  O4  1  0.424  0.500  0.500  1.0
  O  O5  1  0.576  0.000  0.000  1.0
  O  O6  1  0.511  0.500  0.000  1.0
  O  O7  1  0.489  0.000  0.500  1.0
  O  O8  1  0.895  0.313  0.664  1.0
  O  O9  1  0.105  0.813  0.836  1.0
  O  O10  1  0.895  0.687  0.336  1.0
  O  O11  1  0.105  0.187  0.164  1.0
[/CIF]
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