The structure described by HgBa2CuO4 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Cu(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Hg(1) is bonded in a linear geometry to two equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Hg(1) atom. In the second O site, O(2) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form a mixture of corner, face, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba2CuHgO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.934
_cell_length_b   3.934
_cell_length_c   9.828
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   152.073
_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  0.696  1.0
  Ba  Ba1  1  0.500  0.500  0.304  1.0
  Cu  Cu2  1  0.000  0.000  0.500  1.0
  Hg  Hg3  1  0.000  0.000  0.000  1.0
  O  O4  1  0.000  0.000  0.795  1.0
  O  O5  1  0.000  0.000  0.205  1.0
  O  O6  1  0.000  0.500  0.500  1.0
  O  O7  1  0.500  0.000  0.500  1.0
[/CIF]
.
The structure described by HgBa2CuO4 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Cu(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Hg(1) is bonded in a linear geometry to two equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Hg(1) atom. In the second O site, O(2) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form a mixture of corner, face, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba2CuHgO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.934
_cell_length_b   3.934
_cell_length_c   9.828
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   152.073
_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  0.696  1.0
  Ba  Ba1  1  0.500  0.500  0.304  1.0
  Cu  Cu2  1  0.000  0.000  0.500  1.0
  Hg  Hg3  1  0.000  0.000  0.000  1.0
  O  O4  1  0.000  0.000  0.795  1.0
  O  O5  1  0.000  0.000  0.205  1.0
  O  O6  1  0.000  0.500  0.500  1.0
  O  O7  1  0.500  0.000  0.500  1.0
[/CIF]
.