The material described by PrBa2NbCu2O8 crystallizes in the tetragonal I4/mcm space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. Pr(1) is bonded in a body-centered cubic geometry to eight equivalent O(3) atoms. Nb(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NbO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra and corners with two equivalent Cu(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 18°. Cu(1) is bonded to one O(2) and four equivalent O(3) atoms to form CuO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra and corners with four equivalent Cu(1)O5 square pyramids. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(3) is bonded to two equivalent Ba(1), two equivalent Pr(1), and two equivalent Cu(1) atoms to form distorted OBa2Pr2Cu2 octahedra that share corners with four equivalent O(2)Ba4NbCu octahedra, corners with eight equivalent O(3)Ba2Pr2Cu2 octahedra, edges with three equivalent O(3)Ba2Pr2Cu2 octahedra, faces with two equivalent O(2)Ba4NbCu octahedra, and faces with four equivalent O(3)Ba2Pr2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the second O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1) and two equivalent Nb(1) atoms. In the third O site, O(2) is bonded to four equivalent Ba(1), one Nb(1), and one Cu(1) atom to form distorted OBa4NbCu octahedra that share corners with five equivalent O(2)Ba4NbCu octahedra, corners with eight equivalent O(3)Ba2Pr2Cu2 octahedra, edges with four equivalent O(2)Ba4NbCu octahedra, and faces with four equivalent O(3)Ba2Pr2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-55°. is represented by the CIF file [CIF]
data_Ba2PrNb(CuO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.891
_cell_length_b   12.891
_cell_length_c   12.891
_cell_angle_alpha   154.672
_cell_angle_beta   154.672
_cell_angle_gamma   36.123
_symmetry_Int_Tables_number   1
_cell_volume   391.568
_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  0.902  0.402  0.500  1.0
  Ba  Ba1  1  0.402  0.902  0.500  1.0
  Ba  Ba2  1  0.098  0.598  0.500  1.0
  Ba  Ba3  1  0.598  0.098  0.500  1.0
  Pr  Pr4  1  0.750  0.250  0.500  1.0
  Pr  Pr5  1  0.250  0.750  0.500  1.0
  Nb  Nb6  1  0.500  0.500  0.000  1.0
  Nb  Nb7  1  0.000  0.000  0.000  1.0
  Cu  Cu8  1  0.321  0.321  0.000  1.0
  Cu  Cu9  1  0.821  0.821  0.000  1.0
  Cu  Cu10  1  0.679  0.679  0.000  1.0
  Cu  Cu11  1  0.179  0.179  0.000  1.0
  O  O12  1  0.291  0.791  0.081  1.0
  O  O13  1  0.709  0.209  0.919  1.0
  O  O14  1  0.791  0.709  0.500  1.0
  O  O15  1  0.209  0.291  0.500  1.0
  O  O16  1  0.418  0.418  0.000  1.0
  O  O17  1  0.918  0.918  0.000  1.0
  O  O18  1  0.582  0.582  0.000  1.0
  O  O19  1  0.082  0.082  0.000  1.0
  O  O20  1  0.062  0.562  0.997  1.0
  O  O21  1  0.565  0.065  0.003  1.0
  O  O22  1  0.562  0.565  0.500  1.0
  O  O23  1  0.065  0.062  0.500  1.0
  O  O24  1  0.938  0.438  0.003  1.0
  O  O25  1  0.435  0.935  0.997  1.0
  O  O26  1  0.438  0.435  0.500  1.0
  O  O27  1  0.935  0.938  0.500  1.0
[/CIF]
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The material described by PrBa2NbCu2O8 crystallizes in the tetragonal I4/mcm space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. Pr(1) is bonded in a body-centered cubic geometry to eight equivalent O(3) atoms. Nb(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NbO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra and corners with two equivalent Cu(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 18°. Cu(1) is bonded to one O(2) and four equivalent O(3) atoms to form CuO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra and corners with four equivalent Cu(1)O5 square pyramids. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(3) is bonded to two equivalent Ba(1), two equivalent Pr(1), and two equivalent Cu(1) atoms to form distorted OBa2Pr2Cu2 octahedra that share corners with four equivalent O(2)Ba4NbCu octahedra, corners with eight equivalent O(3)Ba2Pr2Cu2 octahedra, edges with three equivalent O(3)Ba2Pr2Cu2 octahedra, faces with two equivalent O(2)Ba4NbCu octahedra, and faces with four equivalent O(3)Ba2Pr2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the second O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1) and two equivalent Nb(1) atoms. In the third O site, O(2) is bonded to four equivalent Ba(1), one Nb(1), and one Cu(1) atom to form distorted OBa4NbCu octahedra that share corners with five equivalent O(2)Ba4NbCu octahedra, corners with eight equivalent O(3)Ba2Pr2Cu2 octahedra, edges with four equivalent O(2)Ba4NbCu octahedra, and faces with four equivalent O(3)Ba2Pr2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-55°. is represented by the CIF file [CIF]
data_Ba2PrNb(CuO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.891
_cell_length_b   12.891
_cell_length_c   12.891
_cell_angle_alpha   154.672
_cell_angle_beta   154.672
_cell_angle_gamma   36.123
_symmetry_Int_Tables_number   1
_cell_volume   391.568
_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  0.902  0.402  0.500  1.0
  Ba  Ba1  1  0.402  0.902  0.500  1.0
  Ba  Ba2  1  0.098  0.598  0.500  1.0
  Ba  Ba3  1  0.598  0.098  0.500  1.0
  Pr  Pr4  1  0.750  0.250  0.500  1.0
  Pr  Pr5  1  0.250  0.750  0.500  1.0
  Nb  Nb6  1  0.500  0.500  0.000  1.0
  Nb  Nb7  1  0.000  0.000  0.000  1.0
  Cu  Cu8  1  0.321  0.321  0.000  1.0
  Cu  Cu9  1  0.821  0.821  0.000  1.0
  Cu  Cu10  1  0.679  0.679  0.000  1.0
  Cu  Cu11  1  0.179  0.179  0.000  1.0
  O  O12  1  0.291  0.791  0.081  1.0
  O  O13  1  0.709  0.209  0.919  1.0
  O  O14  1  0.791  0.709  0.500  1.0
  O  O15  1  0.209  0.291  0.500  1.0
  O  O16  1  0.418  0.418  0.000  1.0
  O  O17  1  0.918  0.918  0.000  1.0
  O  O18  1  0.582  0.582  0.000  1.0
  O  O19  1  0.082  0.082  0.000  1.0
  O  O20  1  0.062  0.562  0.997  1.0
  O  O21  1  0.565  0.065  0.003  1.0
  O  O22  1  0.562  0.565  0.500  1.0
  O  O23  1  0.065  0.062  0.500  1.0
  O  O24  1  0.938  0.438  0.003  1.0
  O  O25  1  0.435  0.935  0.997  1.0
  O  O26  1  0.438  0.435  0.500  1.0
  O  O27  1  0.935  0.938  0.500  1.0
[/CIF]
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