The structure described by Ba2CuO4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one O(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one O(1) atom. In the third O site, O(3) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner, edge, and face-sharing OBa4Cu2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Ba2CuO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.899
_cell_length_b   3.899
_cell_length_c   7.508
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   114.117
_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  0.500  0.500  0.258  1.0
  Ba  Ba1  1  0.500  0.500  0.742  1.0
  Cu  Cu2  1  0.000  0.000  0.000  1.0
  O  O3  1  0.000  0.000  0.603  1.0
  O  O4  1  0.000  0.000  0.397  1.0
  O  O5  1  0.500  1.000  0.000  1.0
  O  O6  1  0.000  0.500  0.000  1.0
[/CIF]
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The structure described by Ba2CuO4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one O(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one O(1) atom. In the third O site, O(3) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner, edge, and face-sharing OBa4Cu2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Ba2CuO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.899
_cell_length_b   3.899
_cell_length_c   7.508
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   114.117
_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  0.500  0.500  0.258  1.0
  Ba  Ba1  1  0.500  0.500  0.742  1.0
  Cu  Cu2  1  0.000  0.000  0.000  1.0
  O  O3  1  0.000  0.000  0.603  1.0
  O  O4  1  0.000  0.000  0.397  1.0
  O  O5  1  0.500  1.000  0.000  1.0
  O  O6  1  0.000  0.500  0.000  1.0
[/CIF]
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