The crystal structure described by Y2HfO5 crystallizes in the orthorhombic Cmcm space group. Y(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(1), and three equivalent O(2) atoms. Hf(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 35°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Y(1) and one Hf(1) atom. In the second O site, O(2) is bonded to three equivalent Y(1) and one Hf(1) atom to form OY3Hf tetrahedra that share  a cornercorner with one O(3)Y2Hf2 tetrahedra, corners with three equivalent O(2)Y3Hf tetrahedra, edges with two equivalent O(3)Y2Hf2 tetrahedra, and edges with two equivalent O(2)Y3Hf tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Hf(1) atoms to form distorted OY2Hf2 tetrahedra that share corners with two equivalent O(3)Y2Hf2 tetrahedra, corners with two equivalent O(2)Y3Hf tetrahedra, and edges with four equivalent O(2)Y3Hf tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y2HfO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.082
_cell_length_b   5.948
_cell_length_c   10.807
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   110.067
_symmetry_Int_Tables_number   1
_cell_volume   246.460
_cell_formula_units_Z   2
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
  Y  Y0  1  0.139  0.279  0.566  1.0
  Y  Y1  1  0.139  0.279  0.934  1.0
  Y  Y2  1  0.861  0.721  0.066  1.0
  Y  Y3  1  0.861  0.721  0.434  1.0
  Hf  Hf4  1  0.177  0.353  0.250  1.0
  Hf  Hf5  1  0.823  0.647  0.750  1.0
  O  O6  1  0.049  0.097  0.119  1.0
  O  O7  1  0.291  0.581  0.412  1.0
  O  O8  1  0.049  0.097  0.381  1.0
  O  O9  1  0.291  0.581  0.088  1.0
  O  O10  1  0.266  0.533  0.750  1.0
  O  O11  1  0.951  0.903  0.619  1.0
  O  O12  1  0.734  0.467  0.250  1.0
  O  O13  1  0.709  0.419  0.588  1.0
  O  O14  1  0.951  0.903  0.881  1.0
  O  O15  1  0.709  0.419  0.912  1.0
[/CIF]
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The crystal structure described by Y2HfO5 crystallizes in the orthorhombic Cmcm space group. Y(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(1), and three equivalent O(2) atoms. Hf(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 35°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Y(1) and one Hf(1) atom. In the second O site, O(2) is bonded to three equivalent Y(1) and one Hf(1) atom to form OY3Hf tetrahedra that share  a cornercorner with one O(3)Y2Hf2 tetrahedra, corners with three equivalent O(2)Y3Hf tetrahedra, edges with two equivalent O(3)Y2Hf2 tetrahedra, and edges with two equivalent O(2)Y3Hf tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Hf(1) atoms to form distorted OY2Hf2 tetrahedra that share corners with two equivalent O(3)Y2Hf2 tetrahedra, corners with two equivalent O(2)Y3Hf tetrahedra, and edges with four equivalent O(2)Y3Hf tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y2HfO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.082
_cell_length_b   5.948
_cell_length_c   10.807
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   110.067
_symmetry_Int_Tables_number   1
_cell_volume   246.460
_cell_formula_units_Z   2
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
  Y  Y0  1  0.139  0.279  0.566  1.0
  Y  Y1  1  0.139  0.279  0.934  1.0
  Y  Y2  1  0.861  0.721  0.066  1.0
  Y  Y3  1  0.861  0.721  0.434  1.0
  Hf  Hf4  1  0.177  0.353  0.250  1.0
  Hf  Hf5  1  0.823  0.647  0.750  1.0
  O  O6  1  0.049  0.097  0.119  1.0
  O  O7  1  0.291  0.581  0.412  1.0
  O  O8  1  0.049  0.097  0.381  1.0
  O  O9  1  0.291  0.581  0.088  1.0
  O  O10  1  0.266  0.533  0.750  1.0
  O  O11  1  0.951  0.903  0.619  1.0
  O  O12  1  0.734  0.467  0.250  1.0
  O  O13  1  0.709  0.419  0.588  1.0
  O  O14  1  0.951  0.903  0.881  1.0
  O  O15  1  0.709  0.419  0.912  1.0
[/CIF]
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