The compound described by ErBa2Cu4O8 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. Er(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing CuO5 square pyramids. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to one O(4) and three equivalent O(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Ba(1) and three equivalent Cu(2) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Cu(1) atoms. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Cu(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 11°. is represented by the CIF file [CIF]
data_Ba2Er(CuO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.869
_cell_length_b   13.869
_cell_length_c   3.873
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   163.872
_symmetry_Int_Tables_number   1
_cell_volume   206.974
_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  0.635  0.365  0.500  1.0
  Ba  Ba1  1  0.365  0.635  0.500  1.0
  Er  Er2  1  0.500  0.500  0.500  1.0
  Cu  Cu3  1  0.061  0.939  0.000  1.0
  Cu  Cu4  1  0.939  0.061  0.000  1.0
  Cu  Cu5  1  0.213  0.787  0.000  1.0
  Cu  Cu6  1  0.787  0.213  0.000  1.0
  O  O7  1  0.718  0.282  0.000  1.0
  O  O8  1  0.282  0.718  0.000  1.0
  O  O9  1  0.551  0.449  0.000  1.0
  O  O10  1  0.449  0.551  0.000  1.0
  O  O11  1  0.051  0.949  0.500  1.0
  O  O12  1  0.949  0.051  0.500  1.0
  O  O13  1  0.145  0.855  0.000  1.0
  O  O14  1  0.855  0.145  0.000  1.0
[/CIF]
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The compound described by ErBa2Cu4O8 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. Er(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing CuO5 square pyramids. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to one O(4) and three equivalent O(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to two equivalent Ba(1) and three equivalent Cu(2) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Cu(1) atoms. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Cu(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Ba(1), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 11°. is represented by the CIF file [CIF]
data_Ba2Er(CuO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.869
_cell_length_b   13.869
_cell_length_c   3.873
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   163.872
_symmetry_Int_Tables_number   1
_cell_volume   206.974
_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  0.635  0.365  0.500  1.0
  Ba  Ba1  1  0.365  0.635  0.500  1.0
  Er  Er2  1  0.500  0.500  0.500  1.0
  Cu  Cu3  1  0.061  0.939  0.000  1.0
  Cu  Cu4  1  0.939  0.061  0.000  1.0
  Cu  Cu5  1  0.213  0.787  0.000  1.0
  Cu  Cu6  1  0.787  0.213  0.000  1.0
  O  O7  1  0.718  0.282  0.000  1.0
  O  O8  1  0.282  0.718  0.000  1.0
  O  O9  1  0.551  0.449  0.000  1.0
  O  O10  1  0.449  0.551  0.000  1.0
  O  O11  1  0.051  0.949  0.500  1.0
  O  O12  1  0.949  0.051  0.500  1.0
  O  O13  1  0.145  0.855  0.000  1.0
  O  O14  1  0.855  0.145  0.000  1.0
[/CIF]
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