The crystal structure described by CuNbO3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 8°. In the second Nb site, Nb(2) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a linear geometry to two equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a linear geometry to one O(1) and one O(2) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Nb(2) and one Cu(2) atom. In the second O site, O(2) is bonded to one Nb(2), two equivalent Nb(1), and one Cu(2) atom to form distorted edge-sharing ONb3Cu tetrahedra. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Nb(1), one Nb(2), and one Cu(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. is represented by the CIF file [CIF]
data_NbCuO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.451
_cell_length_b   6.451
_cell_length_c   6.754
_cell_angle_alpha   90.783
_cell_angle_beta   90.783
_cell_angle_gamma   83.520
_symmetry_Int_Tables_number   1
_cell_volume   279.195
_cell_formula_units_Z   4
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
  Nb  Nb0  1  0.202  0.798  0.000  1.0
  Nb  Nb1  1  0.798  0.202  0.000  1.0
  Nb  Nb2  1  0.747  0.747  0.765  1.0
  Nb  Nb3  1  0.253  0.253  0.235  1.0
  Cu  Cu4  1  0.153  0.847  0.500  1.0
  Cu  Cu5  1  0.847  0.153  0.500  1.0
  Cu  Cu6  1  0.217  0.217  0.709  1.0
  Cu  Cu7  1  0.783  0.783  0.291  1.0
  O  O8  1  0.319  0.319  0.489  1.0
  O  O9  1  0.681  0.681  0.511  1.0
  O  O10  1  0.128  0.128  0.945  1.0
  O  O11  1  0.872  0.872  0.055  1.0
  O  O12  1  0.068  0.739  0.735  1.0
  O  O13  1  0.261  0.932  0.265  1.0
  O  O14  1  0.932  0.261  0.265  1.0
  O  O15  1  0.739  0.068  0.735  1.0
  O  O16  1  0.793  0.470  0.889  1.0
  O  O17  1  0.530  0.207  0.111  1.0
  O  O18  1  0.207  0.530  0.111  1.0
  O  O19  1  0.470  0.793  0.889  1.0
[/CIF]
.
The crystal structure described by CuNbO3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 8°. In the second Nb site, Nb(2) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a linear geometry to two equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a linear geometry to one O(1) and one O(2) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Nb(2) and one Cu(2) atom. In the second O site, O(2) is bonded to one Nb(2), two equivalent Nb(1), and one Cu(2) atom to form distorted edge-sharing ONb3Cu tetrahedra. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Nb(1), one Nb(2), and one Cu(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. is represented by the CIF file [CIF]
data_NbCuO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.451
_cell_length_b   6.451
_cell_length_c   6.754
_cell_angle_alpha   90.783
_cell_angle_beta   90.783
_cell_angle_gamma   83.520
_symmetry_Int_Tables_number   1
_cell_volume   279.195
_cell_formula_units_Z   4
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
  Nb  Nb0  1  0.202  0.798  0.000  1.0
  Nb  Nb1  1  0.798  0.202  0.000  1.0
  Nb  Nb2  1  0.747  0.747  0.765  1.0
  Nb  Nb3  1  0.253  0.253  0.235  1.0
  Cu  Cu4  1  0.153  0.847  0.500  1.0
  Cu  Cu5  1  0.847  0.153  0.500  1.0
  Cu  Cu6  1  0.217  0.217  0.709  1.0
  Cu  Cu7  1  0.783  0.783  0.291  1.0
  O  O8  1  0.319  0.319  0.489  1.0
  O  O9  1  0.681  0.681  0.511  1.0
  O  O10  1  0.128  0.128  0.945  1.0
  O  O11  1  0.872  0.872  0.055  1.0
  O  O12  1  0.068  0.739  0.735  1.0
  O  O13  1  0.261  0.932  0.265  1.0
  O  O14  1  0.932  0.261  0.265  1.0
  O  O15  1  0.739  0.068  0.735  1.0
  O  O16  1  0.793  0.470  0.889  1.0
  O  O17  1  0.530  0.207  0.111  1.0
  O  O18  1  0.207  0.530  0.111  1.0
  O  O19  1  0.470  0.793  0.889  1.0
[/CIF]
.