The structure described by WNb12O33 crystallizes in the monoclinic C2 space group. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(16), one O(17), one O(3), one O(5), and two equivalent O(2) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(6)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra,  a cornercorner with one W(1)O4 tetrahedra, and edges with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-33°. In the second Nb site, Nb(2) is bonded to one O(2), one O(3), one O(6), one O(8), and two equivalent O(16) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-32°. In the third Nb site, Nb(3) is bonded to one O(10), one O(4), one O(6), one O(7), and two equivalent O(15) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  a cornercorner with one W(1)O4 tetrahedra, and edges with two equivalent Nb(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-33°. In the fourth Nb site, Nb(4) is bonded to one O(1), one O(11), one O(8), one O(9), and two equivalent O(14) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the fifth Nb site, Nb(5) is bonded to one O(10), one O(11), one O(13), and three equivalent O(12) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-33°. In the sixth Nb site, Nb(6) is bonded to one O(13), one O(15), one O(5), one O(9), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 5-32°. W(1) is bonded to two equivalent O(17) and two equivalent O(4) atoms to form WO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-45°. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Nb(4) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Nb(3) and one W(1) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(1) and one Nb(6) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Nb(3) and two equivalent Nb(6) atoms. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(2) and one Nb(4) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(4) and one Nb(6) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Nb(3) and one Nb(5) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Nb(4) and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to three equivalent Nb(5) atoms. In the thirteenth O site, O(13) is bonded in a linear geometry to one Nb(5) and one Nb(6) atom. In the fourteenth O site, O(14) is bonded in a linear geometry to two equivalent Nb(4) atoms. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Nb(6) and two equivalent Nb(3) atoms. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Nb(2) atoms. In the seventeenth O site, O(17) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one W(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb12WO33
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.560
_cell_length_b   11.560
_cell_length_c   18.175
_cell_angle_alpha   57.087
_cell_angle_beta   57.087
_cell_angle_gamma   19.274
_symmetry_Int_Tables_number   1
_cell_volume   668.940
_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
  Nb  Nb0  1  0.363  0.372  0.954  1.0
  Nb  Nb1  1  0.628  0.637  0.046  1.0
  Nb  Nb2  1  0.249  0.249  0.862  1.0
  Nb  Nb3  1  0.751  0.751  0.138  1.0
  Nb  Nb4  1  0.136  0.127  0.767  1.0
  Nb  Nb5  1  0.873  0.864  0.233  1.0
  Nb  Nb6  1  0.418  0.418  0.619  1.0
  Nb  Nb7  1  0.582  0.582  0.381  1.0
  Nb  Nb8  1  0.299  0.299  0.527  1.0
  Nb  Nb9  1  0.701  0.701  0.473  1.0
  Nb  Nb10  1  0.465  0.465  0.287  1.0
  Nb  Nb11  1  0.535  0.535  0.713  1.0
  W  W12  1  0.754  0.246  0.000  1.0
  O  O13  1  0.500  0.500  0.500  1.0
  O  O14  1  0.147  0.150  0.008  1.0
  O  O15  1  0.850  0.853  0.992  1.0
  O  O16  1  0.305  0.305  0.917  1.0
  O  O17  1  0.695  0.695  0.083  1.0
  O  O18  1  0.041  0.032  0.900  1.0
  O  O19  1  0.968  0.959  0.100  1.0
  O  O20  1  0.451  0.450  0.845  1.0
  O  O21  1  0.550  0.549  0.155  1.0
  O  O22  1  0.181  0.182  0.821  1.0
  O  O23  1  0.818  0.819  0.179  1.0
  O  O24  1  0.049  0.048  0.730  1.0
  O  O25  1  0.952  0.951  0.270  1.0
  O  O26  1  0.326  0.326  0.750  1.0
  O  O27  1  0.674  0.674  0.250  1.0
  O  O28  1  0.474  0.475  0.675  1.0
  O  O29  1  0.525  0.526  0.325  1.0
  O  O30  1  0.207  0.208  0.651  1.0
  O  O31  1  0.792  0.793  0.349  1.0
  O  O32  1  0.353  0.352  0.575  1.0
  O  O33  1  0.648  0.647  0.425  1.0
  O  O34  1  0.223  0.223  0.478  1.0
  O  O35  1  0.777  0.777  0.522  1.0
  O  O36  1  0.379  0.379  0.405  1.0
  O  O37  1  0.621  0.621  0.595  1.0
  O  O38  1  0.088  0.088  0.373  1.0
  O  O39  1  0.912  0.912  0.627  1.0
  O  O40  1  0.394  0.392  0.234  1.0
  O  O41  1  0.608  0.606  0.766  1.0
  O  O42  1  0.275  0.276  0.103  1.0
  O  O43  1  0.724  0.725  0.897  1.0
  O  O44  1  0.423  0.435  0.012  1.0
  O  O45  1  0.565  0.577  0.988  1.0
[/CIF]
.
The structure described by WNb12O33 crystallizes in the monoclinic C2 space group. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(16), one O(17), one O(3), one O(5), and two equivalent O(2) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(6)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra,  a cornercorner with one W(1)O4 tetrahedra, and edges with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-33°. In the second Nb site, Nb(2) is bonded to one O(2), one O(3), one O(6), one O(8), and two equivalent O(16) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-32°. In the third Nb site, Nb(3) is bonded to one O(10), one O(4), one O(6), one O(7), and two equivalent O(15) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(5)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra,  a cornercorner with one W(1)O4 tetrahedra, and edges with two equivalent Nb(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-33°. In the fourth Nb site, Nb(4) is bonded to one O(1), one O(11), one O(8), one O(9), and two equivalent O(14) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the fifth Nb site, Nb(5) is bonded to one O(10), one O(11), one O(13), and three equivalent O(12) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-33°. In the sixth Nb site, Nb(6) is bonded to one O(13), one O(15), one O(5), one O(9), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 5-32°. W(1) is bonded to two equivalent O(17) and two equivalent O(4) atoms to form WO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-45°. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Nb(4) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Nb(3) and one W(1) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(1) and one Nb(6) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Nb(3) and two equivalent Nb(6) atoms. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(2) and one Nb(4) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(4) and one Nb(6) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Nb(3) and one Nb(5) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Nb(4) and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to three equivalent Nb(5) atoms. In the thirteenth O site, O(13) is bonded in a linear geometry to one Nb(5) and one Nb(6) atom. In the fourteenth O site, O(14) is bonded in a linear geometry to two equivalent Nb(4) atoms. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Nb(6) and two equivalent Nb(3) atoms. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Nb(2) atoms. In the seventeenth O site, O(17) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one W(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb12WO33
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.560
_cell_length_b   11.560
_cell_length_c   18.175
_cell_angle_alpha   57.087
_cell_angle_beta   57.087
_cell_angle_gamma   19.274
_symmetry_Int_Tables_number   1
_cell_volume   668.940
_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
  Nb  Nb0  1  0.363  0.372  0.954  1.0
  Nb  Nb1  1  0.628  0.637  0.046  1.0
  Nb  Nb2  1  0.249  0.249  0.862  1.0
  Nb  Nb3  1  0.751  0.751  0.138  1.0
  Nb  Nb4  1  0.136  0.127  0.767  1.0
  Nb  Nb5  1  0.873  0.864  0.233  1.0
  Nb  Nb6  1  0.418  0.418  0.619  1.0
  Nb  Nb7  1  0.582  0.582  0.381  1.0
  Nb  Nb8  1  0.299  0.299  0.527  1.0
  Nb  Nb9  1  0.701  0.701  0.473  1.0
  Nb  Nb10  1  0.465  0.465  0.287  1.0
  Nb  Nb11  1  0.535  0.535  0.713  1.0
  W  W12  1  0.754  0.246  0.000  1.0
  O  O13  1  0.500  0.500  0.500  1.0
  O  O14  1  0.147  0.150  0.008  1.0
  O  O15  1  0.850  0.853  0.992  1.0
  O  O16  1  0.305  0.305  0.917  1.0
  O  O17  1  0.695  0.695  0.083  1.0
  O  O18  1  0.041  0.032  0.900  1.0
  O  O19  1  0.968  0.959  0.100  1.0
  O  O20  1  0.451  0.450  0.845  1.0
  O  O21  1  0.550  0.549  0.155  1.0
  O  O22  1  0.181  0.182  0.821  1.0
  O  O23  1  0.818  0.819  0.179  1.0
  O  O24  1  0.049  0.048  0.730  1.0
  O  O25  1  0.952  0.951  0.270  1.0
  O  O26  1  0.326  0.326  0.750  1.0
  O  O27  1  0.674  0.674  0.250  1.0
  O  O28  1  0.474  0.475  0.675  1.0
  O  O29  1  0.525  0.526  0.325  1.0
  O  O30  1  0.207  0.208  0.651  1.0
  O  O31  1  0.792  0.793  0.349  1.0
  O  O32  1  0.353  0.352  0.575  1.0
  O  O33  1  0.648  0.647  0.425  1.0
  O  O34  1  0.223  0.223  0.478  1.0
  O  O35  1  0.777  0.777  0.522  1.0
  O  O36  1  0.379  0.379  0.405  1.0
  O  O37  1  0.621  0.621  0.595  1.0
  O  O38  1  0.088  0.088  0.373  1.0
  O  O39  1  0.912  0.912  0.627  1.0
  O  O40  1  0.394  0.392  0.234  1.0
  O  O41  1  0.608  0.606  0.766  1.0
  O  O42  1  0.275  0.276  0.103  1.0
  O  O43  1  0.724  0.725  0.897  1.0
  O  O44  1  0.423  0.435  0.012  1.0
  O  O45  1  0.565  0.577  0.988  1.0
[/CIF]
.