The crystal structure described by CaNb2CuO7Br crystallizes in the tetragonal P4/mmm space group. Ca(1) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form CaO12 cuboctahedra that share corners with four equivalent Ca(1)O12 cuboctahedra, faces with four equivalent Ca(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form distorted NbO6 octahedra that share corners with five equivalent Nb(1)O6 octahedra and faces with four equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-20°. Cu(1) is bonded in a distorted linear geometry to two equivalent O(2) and four equivalent Br(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and two equivalent Nb(1) atoms to form distorted OCa2Nb2 trigonal pyramids that share corners with four equivalent O(3)Ca4Nb2 octahedra, corners with ten equivalent O(1)Ca2Nb2 trigonal pyramids, edges with five equivalent O(1)Ca2Nb2 trigonal pyramids, and faces with two equivalent O(3)Ca4Nb2 octahedra. The corner-sharing octahedral tilt angles are 58°. In the second O site, O(2) is bonded in a linear geometry to one Nb(1) and one Cu(1) atom. In the third O site, O(3) is bonded to four equivalent Ca(1) and two equivalent Nb(1) atoms to form distorted OCa4Nb2 octahedra that share corners with four equivalent O(3)Ca4Nb2 octahedra, corners with sixteen equivalent O(1)Ca2Nb2 trigonal pyramids, edges with four equivalent O(3)Ca4Nb2 octahedra, and faces with eight equivalent O(1)Ca2Nb2 trigonal pyramids. The corner-sharing octahedra are not tilted. Br(1) is bonded in a square co-planar geometry to four equivalent Cu(1) atoms. is represented by the CIF card [CIF]
data_CaNb2CuBrO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.958
_cell_length_b   3.958
_cell_length_c   11.569
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   181.207
_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
  Ca  Ca0  1  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.500  0.500  0.816  1.0
  Nb  Nb2  1  0.500  0.500  0.184  1.0
  Cu  Cu3  1  0.500  0.500  0.500  1.0
  Br  Br4  1  0.000  0.000  0.500  1.0
  O  O5  1  0.000  0.500  0.154  1.0
  O  O6  1  0.500  0.000  0.154  1.0
  O  O7  1  0.500  0.500  0.345  1.0
  O  O8  1  0.500  0.000  0.846  1.0
  O  O9  1  0.000  0.500  0.846  1.0
  O  O10  1  0.500  0.500  0.655  1.0
  O  O11  1  0.500  0.500  0.000  1.0
[/CIF]
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The crystal structure described by CaNb2CuO7Br crystallizes in the tetragonal P4/mmm space group. Ca(1) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form CaO12 cuboctahedra that share corners with four equivalent Ca(1)O12 cuboctahedra, faces with four equivalent Ca(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form distorted NbO6 octahedra that share corners with five equivalent Nb(1)O6 octahedra and faces with four equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-20°. Cu(1) is bonded in a distorted linear geometry to two equivalent O(2) and four equivalent Br(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and two equivalent Nb(1) atoms to form distorted OCa2Nb2 trigonal pyramids that share corners with four equivalent O(3)Ca4Nb2 octahedra, corners with ten equivalent O(1)Ca2Nb2 trigonal pyramids, edges with five equivalent O(1)Ca2Nb2 trigonal pyramids, and faces with two equivalent O(3)Ca4Nb2 octahedra. The corner-sharing octahedral tilt angles are 58°. In the second O site, O(2) is bonded in a linear geometry to one Nb(1) and one Cu(1) atom. In the third O site, O(3) is bonded to four equivalent Ca(1) and two equivalent Nb(1) atoms to form distorted OCa4Nb2 octahedra that share corners with four equivalent O(3)Ca4Nb2 octahedra, corners with sixteen equivalent O(1)Ca2Nb2 trigonal pyramids, edges with four equivalent O(3)Ca4Nb2 octahedra, and faces with eight equivalent O(1)Ca2Nb2 trigonal pyramids. The corner-sharing octahedra are not tilted. Br(1) is bonded in a square co-planar geometry to four equivalent Cu(1) atoms. is represented by the CIF card [CIF]
data_CaNb2CuBrO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.958
_cell_length_b   3.958
_cell_length_c   11.569
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   181.207
_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
  Ca  Ca0  1  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.500  0.500  0.816  1.0
  Nb  Nb2  1  0.500  0.500  0.184  1.0
  Cu  Cu3  1  0.500  0.500  0.500  1.0
  Br  Br4  1  0.000  0.000  0.500  1.0
  O  O5  1  0.000  0.500  0.154  1.0
  O  O6  1  0.500  0.000  0.154  1.0
  O  O7  1  0.500  0.500  0.345  1.0
  O  O8  1  0.500  0.000  0.846  1.0
  O  O9  1  0.000  0.500  0.846  1.0
  O  O10  1  0.500  0.500  0.655  1.0
  O  O11  1  0.500  0.500  0.000  1.0
[/CIF]
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