The material described by Na12NbO7 is Calaverite-derived structured and crystallizes in the trigonal R-3 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted T-shaped geometry to three equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a distorted trigonal non-coplanar geometry to one O(2) and two equivalent O(1) atoms. Nb(1) is bonded in an octahedral geometry to six equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(2), three equivalent Na(1), and one Nb(1) atom to form ONa5Nb octahedra that share corners with three equivalent O(1)Na5Nb octahedra,  an edgeedge with one O(2)Na6 octahedra, and edges with five equivalent O(1)Na5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to six equivalent Na(2) atoms to form distorted edge-sharing ONa6 octahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na12NbO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.521
_cell_length_b   7.521
_cell_length_c   7.521
_cell_angle_alpha   106.145
_cell_angle_beta   106.145
_cell_angle_gamma   106.145
_symmetry_Int_Tables_number   1
_cell_volume   362.243
_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
  Na  Na0  1  0.205  0.677  0.069  1.0
  Na  Na1  1  0.931  0.795  0.323  1.0
  Na  Na2  1  0.633  0.834  0.570  1.0
  Na  Na3  1  0.430  0.367  0.166  1.0
  Na  Na4  1  0.323  0.931  0.795  1.0
  Na  Na5  1  0.166  0.430  0.367  1.0
  Na  Na6  1  0.834  0.570  0.633  1.0
  Na  Na7  1  0.677  0.069  0.205  1.0
  Na  Na8  1  0.570  0.633  0.834  1.0
  Na  Na9  1  0.367  0.166  0.430  1.0
  Na  Na10  1  0.069  0.205  0.677  1.0
  Na  Na11  1  0.795  0.323  0.931  1.0
  Nb  Nb12  1  0.000  0.000  0.000  1.0
  O  O13  1  0.095  0.294  0.018  1.0
  O  O14  1  0.982  0.905  0.706  1.0
  O  O15  1  0.706  0.982  0.905  1.0
  O  O16  1  0.500  0.500  0.500  1.0
  O  O17  1  0.294  0.018  0.095  1.0
  O  O18  1  0.018  0.095  0.294  1.0
  O  O19  1  0.905  0.706  0.982  1.0
[/CIF]
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The material described by Na12NbO7 is Calaverite-derived structured and crystallizes in the trigonal R-3 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted T-shaped geometry to three equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a distorted trigonal non-coplanar geometry to one O(2) and two equivalent O(1) atoms. Nb(1) is bonded in an octahedral geometry to six equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(2), three equivalent Na(1), and one Nb(1) atom to form ONa5Nb octahedra that share corners with three equivalent O(1)Na5Nb octahedra,  an edgeedge with one O(2)Na6 octahedra, and edges with five equivalent O(1)Na5Nb octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to six equivalent Na(2) atoms to form distorted edge-sharing ONa6 octahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na12NbO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.521
_cell_length_b   7.521
_cell_length_c   7.521
_cell_angle_alpha   106.145
_cell_angle_beta   106.145
_cell_angle_gamma   106.145
_symmetry_Int_Tables_number   1
_cell_volume   362.243
_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
  Na  Na0  1  0.205  0.677  0.069  1.0
  Na  Na1  1  0.931  0.795  0.323  1.0
  Na  Na2  1  0.633  0.834  0.570  1.0
  Na  Na3  1  0.430  0.367  0.166  1.0
  Na  Na4  1  0.323  0.931  0.795  1.0
  Na  Na5  1  0.166  0.430  0.367  1.0
  Na  Na6  1  0.834  0.570  0.633  1.0
  Na  Na7  1  0.677  0.069  0.205  1.0
  Na  Na8  1  0.570  0.633  0.834  1.0
  Na  Na9  1  0.367  0.166  0.430  1.0
  Na  Na10  1  0.069  0.205  0.677  1.0
  Na  Na11  1  0.795  0.323  0.931  1.0
  Nb  Nb12  1  0.000  0.000  0.000  1.0
  O  O13  1  0.095  0.294  0.018  1.0
  O  O14  1  0.982  0.905  0.706  1.0
  O  O15  1  0.706  0.982  0.905  1.0
  O  O16  1  0.500  0.500  0.500  1.0
  O  O17  1  0.294  0.018  0.095  1.0
  O  O18  1  0.018  0.095  0.294  1.0
  O  O19  1  0.905  0.706  0.982  1.0
[/CIF]
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