The material described by YBa2Cu3O6 crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and four equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(6) atoms. Y(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(5), two equivalent O(2), and two equivalent O(4) atoms to form corner-sharing CuO5 trigonal bipyramids. In the second Cu site, Cu(2) is bonded in a distorted T-shaped geometry to one O(6) and two equivalent O(3) atoms. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to one O(5), one O(6), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Cu(3) atoms to form a mixture of distorted edge, face, and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ba(2), two equivalent Y(1), and two equivalent Cu(2) atoms. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms. In the fifth O site, O(5) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(3) atom to form a mixture of distorted edge, face, and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-65°. In the sixth O site, O(6) is bonded to four equivalent Ba(2), one Cu(2), and one Cu(3) atom to form a mixture of edge, face, and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. is represented by the CIF file [CIF]
data_Ba2Y(CuO2)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.886
_cell_length_b   3.911
_cell_length_c   11.841
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   179.987
_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  0.823  1.0
  Ba  Ba1  1  0.500  0.500  0.169  1.0
  Y  Y2  1  0.500  0.500  0.513  1.0
  Cu  Cu3  1  0.000  0.000  0.645  1.0
  Cu  Cu4  1  0.000  0.000  0.346  1.0
  Cu  Cu5  1  0.000  0.000  0.002  1.0
  O  O6  1  0.000  0.500  0.004  1.0
  O  O7  1  0.500  0.000  0.626  1.0
  O  O8  1  0.500  0.000  0.382  1.0
  O  O9  1  0.000  0.500  0.602  1.0
  O  O10  1  0.000  0.000  0.841  1.0
  O  O11  1  0.000  0.000  0.169  1.0
[/CIF]
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The material described by YBa2Cu3O6 crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and four equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(6) atoms. Y(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(5), two equivalent O(2), and two equivalent O(4) atoms to form corner-sharing CuO5 trigonal bipyramids. In the second Cu site, Cu(2) is bonded in a distorted T-shaped geometry to one O(6) and two equivalent O(3) atoms. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to one O(5), one O(6), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Cu(3) atoms to form a mixture of distorted edge, face, and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ba(2), two equivalent Y(1), and two equivalent Cu(2) atoms. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Ba(1), two equivalent Y(1), and two equivalent Cu(1) atoms. In the fifth O site, O(5) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(3) atom to form a mixture of distorted edge, face, and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-65°. In the sixth O site, O(6) is bonded to four equivalent Ba(2), one Cu(2), and one Cu(3) atom to form a mixture of edge, face, and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. is represented by the CIF file [CIF]
data_Ba2Y(CuO2)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.886
_cell_length_b   3.911
_cell_length_c   11.841
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   179.987
_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  0.823  1.0
  Ba  Ba1  1  0.500  0.500  0.169  1.0
  Y  Y2  1  0.500  0.500  0.513  1.0
  Cu  Cu3  1  0.000  0.000  0.645  1.0
  Cu  Cu4  1  0.000  0.000  0.346  1.0
  Cu  Cu5  1  0.000  0.000  0.002  1.0
  O  O6  1  0.000  0.500  0.004  1.0
  O  O7  1  0.500  0.000  0.626  1.0
  O  O8  1  0.500  0.000  0.382  1.0
  O  O9  1  0.000  0.500  0.602  1.0
  O  O10  1  0.000  0.000  0.841  1.0
  O  O11  1  0.000  0.000  0.169  1.0
[/CIF]
.