The compound described by Rb2Hf2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to eight equivalent O(1) atoms to form distorted RbO8 hexagonal bipyramids that share corners with eight equivalent Rb(2)O12 cuboctahedra, edges with four equivalent Rb(1)O8 hexagonal bipyramids, edges with eight equivalent Hf(1)O5 square pyramids, and faces with two equivalent Rb(2)O12 cuboctahedra. In the second Rb site, Rb(2) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form RbO12 cuboctahedra that share corners with four equivalent Rb(2)O12 cuboctahedra, corners with eight equivalent Rb(1)O8 hexagonal bipyramids, faces with four equivalent Rb(2)O12 cuboctahedra, faces with two equivalent Rb(1)O8 hexagonal bipyramids, and faces with eight equivalent Hf(1)O5 square pyramids. Hf(1) is bonded to one O(2) and four equivalent O(1) atoms to form HfO5 square pyramids that share corners with five equivalent Hf(1)O5 square pyramids, edges with four equivalent Rb(1)O8 hexagonal bipyramids, and faces with four equivalent Rb(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Hf(1) atoms. In the second O site, O(2) is bonded to four equivalent Rb(2) and two equivalent Hf(1) atoms to form a mixture of distorted edge and corner-sharing ORb4Hf2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb2Hf2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.032
_cell_length_b   4.032
_cell_length_c   9.014
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   146.504
_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
  Rb  Rb0  1  0.000  0.000  0.000  1.0
  Rb  Rb1  1  0.000  0.000  0.500  1.0
  Hf  Hf2  1  0.500  0.500  0.280  1.0
  Hf  Hf3  1  0.500  0.500  0.720  1.0
  O  O4  1  0.500  0.000  0.236  1.0
  O  O5  1  0.500  0.000  0.764  1.0
  O  O6  1  0.500  0.500  0.500  1.0
  O  O7  1  0.000  0.500  0.236  1.0
  O  O8  1  0.000  0.500  0.764  1.0
[/CIF]
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The compound described by Rb2Hf2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to eight equivalent O(1) atoms to form distorted RbO8 hexagonal bipyramids that share corners with eight equivalent Rb(2)O12 cuboctahedra, edges with four equivalent Rb(1)O8 hexagonal bipyramids, edges with eight equivalent Hf(1)O5 square pyramids, and faces with two equivalent Rb(2)O12 cuboctahedra. In the second Rb site, Rb(2) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form RbO12 cuboctahedra that share corners with four equivalent Rb(2)O12 cuboctahedra, corners with eight equivalent Rb(1)O8 hexagonal bipyramids, faces with four equivalent Rb(2)O12 cuboctahedra, faces with two equivalent Rb(1)O8 hexagonal bipyramids, and faces with eight equivalent Hf(1)O5 square pyramids. Hf(1) is bonded to one O(2) and four equivalent O(1) atoms to form HfO5 square pyramids that share corners with five equivalent Hf(1)O5 square pyramids, edges with four equivalent Rb(1)O8 hexagonal bipyramids, and faces with four equivalent Rb(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Hf(1) atoms. In the second O site, O(2) is bonded to four equivalent Rb(2) and two equivalent Hf(1) atoms to form a mixture of distorted edge and corner-sharing ORb4Hf2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb2Hf2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.032
_cell_length_b   4.032
_cell_length_c   9.014
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   146.504
_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
  Rb  Rb0  1  0.000  0.000  0.000  1.0
  Rb  Rb1  1  0.000  0.000  0.500  1.0
  Hf  Hf2  1  0.500  0.500  0.280  1.0
  Hf  Hf3  1  0.500  0.500  0.720  1.0
  O  O4  1  0.500  0.000  0.236  1.0
  O  O5  1  0.500  0.000  0.764  1.0
  O  O6  1  0.500  0.500  0.500  1.0
  O  O7  1  0.000  0.500  0.236  1.0
  O  O8  1  0.000  0.500  0.764  1.0
[/CIF]
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