The structure described by Ba3Cr2O8 crystallizes in the trigonal R-3m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1) and nine equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share edges with six equivalent Ba(2)O12 cuboctahedra and edges with six equivalent Cr(1)O4 tetrahedra. Cr(1) is bonded to one O(1) and three equivalent O(2) atoms to form CrO4 tetrahedra that share edges with three equivalent Ba(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), three equivalent Ba(2), and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Cr(1) atom. is represented by the CIF card [CIF]
data_Ba3Cr2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.906
_cell_length_b   7.906
_cell_length_c   7.906
_cell_angle_alpha   42.749
_cell_angle_beta   42.749
_cell_angle_gamma   42.749
_symmetry_Int_Tables_number   1
_cell_volume   206.276
_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
  Ba  Ba0  1  0.794  0.794  0.794  1.0
  Ba  Ba1  1  0.206  0.206  0.206  1.0
  Ba  Ba2  1  1.000  1.000  1.000  1.0
  Cr  Cr3  1  0.593  0.593  0.593  1.0
  Cr  Cr4  1  0.407  0.407  0.407  1.0
  O  O5  1  0.671  0.671  0.671  1.0
  O  O6  1  0.329  0.329  0.329  1.0
  O  O7  1  0.274  0.274  0.756  1.0
  O  O8  1  0.274  0.756  0.274  1.0
  O  O9  1  0.756  0.274  0.274  1.0
  O  O10  1  0.726  0.244  0.726  1.0
  O  O11  1  0.726  0.726  0.244  1.0
  O  O12  1  0.244  0.726  0.726  1.0
[/CIF]
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The structure described by Ba3Cr2O8 crystallizes in the trigonal R-3m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1) and nine equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share edges with six equivalent Ba(2)O12 cuboctahedra and edges with six equivalent Cr(1)O4 tetrahedra. Cr(1) is bonded to one O(1) and three equivalent O(2) atoms to form CrO4 tetrahedra that share edges with three equivalent Ba(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), three equivalent Ba(2), and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Cr(1) atom. is represented by the CIF card [CIF]
data_Ba3Cr2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.906
_cell_length_b   7.906
_cell_length_c   7.906
_cell_angle_alpha   42.749
_cell_angle_beta   42.749
_cell_angle_gamma   42.749
_symmetry_Int_Tables_number   1
_cell_volume   206.276
_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
  Ba  Ba0  1  0.794  0.794  0.794  1.0
  Ba  Ba1  1  0.206  0.206  0.206  1.0
  Ba  Ba2  1  1.000  1.000  1.000  1.0
  Cr  Cr3  1  0.593  0.593  0.593  1.0
  Cr  Cr4  1  0.407  0.407  0.407  1.0
  O  O5  1  0.671  0.671  0.671  1.0
  O  O6  1  0.329  0.329  0.329  1.0
  O  O7  1  0.274  0.274  0.756  1.0
  O  O8  1  0.274  0.756  0.274  1.0
  O  O9  1  0.756  0.274  0.274  1.0
  O  O10  1  0.726  0.244  0.726  1.0
  O  O11  1  0.726  0.726  0.244  1.0
  O  O12  1  0.244  0.726  0.726  1.0
[/CIF]
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