The structure described by BaYCr4O7 crystallizes in the hexagonal P6_3mc space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(3) and six equivalent O(1) atoms. Y(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form YO6 octahedra that share corners with three equivalent Cr(2)O4 tetrahedra and corners with nine equivalent Cr(1)O4 tetrahedra. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CrO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and corners with four equivalent Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-59°. In the second Cr site, Cr(2) is bonded to one O(2) and three equivalent O(1) atoms to form CrO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra and corners with six equivalent Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), one Cr(1), and one Cr(2) atom. In the second O site, O(2) is bonded to one Cr(2) and three equivalent Cr(1) atoms to form corner-sharing OCr4 tetrahedra. In the third O site, O(3) is bonded to one Ba(1), one Y(1), and two equivalent Cr(1) atoms to form distorted OBaYCr2 trigonal pyramids that share corners with two equivalent O(2)Cr4 tetrahedra, corners with two equivalent O(3)BaYCr2 trigonal pyramids, and edges with two equivalent O(3)BaYCr2 trigonal pyramids. is represented by the CIF file [CIF]
data_BaYCr4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.363
_cell_length_b   6.363
_cell_length_c   11.101
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   389.230
_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
  Ba  Ba0  1  0.667  0.333  0.472  1.0
  Ba  Ba1  1  0.333  0.667  0.972  1.0
  Y  Y2  1  0.667  0.333  0.880  1.0
  Y  Y3  1  0.333  0.667  0.380  1.0
  Cr  Cr4  1  0.823  0.177  0.183  1.0
  Cr  Cr5  1  0.646  0.823  0.683  1.0
  Cr  Cr6  1  0.177  0.354  0.683  1.0
  Cr  Cr7  1  0.823  0.646  0.183  1.0
  Cr  Cr8  1  0.354  0.177  0.183  1.0
  Cr  Cr9  1  0.177  0.823  0.683  1.0
  Cr  Cr10  1  0.000  0.000  0.433  1.0
  Cr  Cr11  1  0.000  0.000  0.933  1.0
  O  O12  1  0.839  0.161  0.005  1.0
  O  O13  1  0.679  0.839  0.505  1.0
  O  O14  1  0.161  0.321  0.505  1.0
  O  O15  1  0.839  0.679  0.005  1.0
  O  O16  1  0.321  0.161  0.005  1.0
  O  O17  1  0.161  0.839  0.505  1.0
  O  O18  1  0.000  0.000  0.738  1.0
  O  O19  1  0.000  0.000  0.238  1.0
  O  O20  1  0.512  0.488  0.283  1.0
  O  O21  1  0.023  0.512  0.783  1.0
  O  O22  1  0.488  0.977  0.783  1.0
  O  O23  1  0.512  0.023  0.283  1.0
  O  O24  1  0.488  0.512  0.783  1.0
  O  O25  1  0.977  0.488  0.283  1.0
[/CIF]
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The structure described by BaYCr4O7 crystallizes in the hexagonal P6_3mc space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(3) and six equivalent O(1) atoms. Y(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form YO6 octahedra that share corners with three equivalent Cr(2)O4 tetrahedra and corners with nine equivalent Cr(1)O4 tetrahedra. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CrO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and corners with four equivalent Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-59°. In the second Cr site, Cr(2) is bonded to one O(2) and three equivalent O(1) atoms to form CrO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra and corners with six equivalent Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), one Cr(1), and one Cr(2) atom. In the second O site, O(2) is bonded to one Cr(2) and three equivalent Cr(1) atoms to form corner-sharing OCr4 tetrahedra. In the third O site, O(3) is bonded to one Ba(1), one Y(1), and two equivalent Cr(1) atoms to form distorted OBaYCr2 trigonal pyramids that share corners with two equivalent O(2)Cr4 tetrahedra, corners with two equivalent O(3)BaYCr2 trigonal pyramids, and edges with two equivalent O(3)BaYCr2 trigonal pyramids. is represented by the CIF file [CIF]
data_BaYCr4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.363
_cell_length_b   6.363
_cell_length_c   11.101
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   389.230
_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
  Ba  Ba0  1  0.667  0.333  0.472  1.0
  Ba  Ba1  1  0.333  0.667  0.972  1.0
  Y  Y2  1  0.667  0.333  0.880  1.0
  Y  Y3  1  0.333  0.667  0.380  1.0
  Cr  Cr4  1  0.823  0.177  0.183  1.0
  Cr  Cr5  1  0.646  0.823  0.683  1.0
  Cr  Cr6  1  0.177  0.354  0.683  1.0
  Cr  Cr7  1  0.823  0.646  0.183  1.0
  Cr  Cr8  1  0.354  0.177  0.183  1.0
  Cr  Cr9  1  0.177  0.823  0.683  1.0
  Cr  Cr10  1  0.000  0.000  0.433  1.0
  Cr  Cr11  1  0.000  0.000  0.933  1.0
  O  O12  1  0.839  0.161  0.005  1.0
  O  O13  1  0.679  0.839  0.505  1.0
  O  O14  1  0.161  0.321  0.505  1.0
  O  O15  1  0.839  0.679  0.005  1.0
  O  O16  1  0.321  0.161  0.005  1.0
  O  O17  1  0.161  0.839  0.505  1.0
  O  O18  1  0.000  0.000  0.738  1.0
  O  O19  1  0.000  0.000  0.238  1.0
  O  O20  1  0.512  0.488  0.283  1.0
  O  O21  1  0.023  0.512  0.783  1.0
  O  O22  1  0.488  0.977  0.783  1.0
  O  O23  1  0.512  0.023  0.283  1.0
  O  O24  1  0.488  0.512  0.783  1.0
  O  O25  1  0.977  0.488  0.283  1.0
[/CIF]
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