The compound described by Nb12O29 crystallizes in the monoclinic C2/m space group. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(7), two equivalent O(4), and two equivalent O(6) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(8), and two equivalent O(2) atoms. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to one O(2), one O(5), one O(6), one O(9), and two equivalent O(3) atoms. In the fourth Nb site, Nb(4) is bonded to one O(10), one O(11), one O(15), one O(7), and two equivalent O(13) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-32°. In the fifth Nb site, Nb(5) is bonded to one O(13), one O(14), one O(15), one O(8), and two equivalent O(11) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 5-32°. In the sixth Nb site, Nb(6) is bonded to one O(1), one O(10), one O(14), one O(9), and two equivalent O(12) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-15°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Nb(6) atoms. In the second O site, O(2) is bonded to one Nb(1), one Nb(3), and two equivalent Nb(2) atoms to form distorted corner-sharing ONb4 tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(3) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Nb(3) and two equivalent Nb(1) atoms. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(1) and one Nb(4) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(2) and one Nb(5) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(3) and one Nb(6) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Nb(4) and one Nb(6) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Nb(4) and two equivalent Nb(5) atoms. In the twelfth O site, O(12) is bonded in a linear geometry to two equivalent Nb(6) atoms. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Nb(5) and two equivalent Nb(4) atoms. In the fourteenth O site, O(14) is bonded in a linear geometry to one Nb(5) and one Nb(6) atom. In the fifteenth O site, O(15) is bonded in a linear geometry to one Nb(4) and one Nb(5) atom. is represented by the CIF card [CIF]
data_Nb12O29
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.741
_cell_length_b   10.741
_cell_length_c   16.013
_cell_angle_alpha   67.306
_cell_angle_beta   67.306
_cell_angle_gamma   20.759
_symmetry_Int_Tables_number   1
_cell_volume   602.313
_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  0.067  0.067  0.399  1.0
  Nb  Nb1  1  0.698  0.698  0.401  1.0
  Nb  Nb2  1  0.880  0.880  0.403  1.0
  Nb  Nb3  1  0.144  0.144  0.129  1.0
  Nb  Nb4  1  0.776  0.776  0.133  1.0
  Nb  Nb5  1  0.960  0.960  0.131  1.0
  Nb  Nb6  1  0.933  0.933  0.601  1.0
  Nb  Nb7  1  0.302  0.302  0.599  1.0
  Nb  Nb8  1  0.120  0.120  0.597  1.0
  Nb  Nb9  1  0.856  0.856  0.871  1.0
  Nb  Nb10  1  0.224  0.224  0.867  1.0
  Nb  Nb11  1  0.040  0.040  0.869  1.0
  O  O12  1  0.000  0.000  0.000  1.0
  O  O13  1  0.166  0.166  0.428  1.0
  O  O14  1  0.367  0.367  0.442  1.0
  O  O15  1  0.587  0.587  0.414  1.0
  O  O16  1  0.781  0.781  0.416  1.0
  O  O17  1  0.970  0.970  0.437  1.0
  O  O18  1  0.100  0.100  0.276  1.0
  O  O19  1  0.729  0.729  0.278  1.0
  O  O20  1  0.922  0.922  0.282  1.0
  O  O21  1  0.055  0.055  0.135  1.0
  O  O22  1  0.248  0.248  0.141  1.0
  O  O23  1  0.454  0.454  0.149  1.0
  O  O24  1  0.666  0.666  0.139  1.0
  O  O25  1  0.861  0.861  0.139  1.0
  O  O26  1  0.188  0.188  0.999  1.0
  O  O27  1  0.834  0.834  0.572  1.0
  O  O28  1  0.633  0.633  0.558  1.0
  O  O29  1  0.413  0.413  0.586  1.0
  O  O30  1  0.219  0.219  0.584  1.0
  O  O31  1  0.030  0.030  0.563  1.0
  O  O32  1  0.900  0.900  0.724  1.0
  O  O33  1  0.271  0.271  0.722  1.0
  O  O34  1  0.078  0.078  0.718  1.0
  O  O35  1  0.945  0.945  0.865  1.0
  O  O36  1  0.752  0.752  0.859  1.0
  O  O37  1  0.546  0.546  0.851  1.0
  O  O38  1  0.334  0.334  0.861  1.0
  O  O39  1  0.139  0.139  0.861  1.0
  O  O40  1  0.812  0.812  0.001  1.0
[/CIF]
.
The compound described by Nb12O29 crystallizes in the monoclinic C2/m space group. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(7), two equivalent O(4), and two equivalent O(6) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(8), and two equivalent O(2) atoms. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to one O(2), one O(5), one O(6), one O(9), and two equivalent O(3) atoms. In the fourth Nb site, Nb(4) is bonded to one O(10), one O(11), one O(15), one O(7), and two equivalent O(13) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-32°. In the fifth Nb site, Nb(5) is bonded to one O(13), one O(14), one O(15), one O(8), and two equivalent O(11) atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 5-32°. In the sixth Nb site, Nb(6) is bonded to one O(1), one O(10), one O(14), one O(9), and two equivalent O(12) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-15°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Nb(6) atoms. In the second O site, O(2) is bonded to one Nb(1), one Nb(3), and two equivalent Nb(2) atoms to form distorted corner-sharing ONb4 tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(3) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Nb(3) and two equivalent Nb(1) atoms. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(1) and one Nb(4) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(2) and one Nb(5) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(3) and one Nb(6) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Nb(4) and one Nb(6) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Nb(4) and two equivalent Nb(5) atoms. In the twelfth O site, O(12) is bonded in a linear geometry to two equivalent Nb(6) atoms. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Nb(5) and two equivalent Nb(4) atoms. In the fourteenth O site, O(14) is bonded in a linear geometry to one Nb(5) and one Nb(6) atom. In the fifteenth O site, O(15) is bonded in a linear geometry to one Nb(4) and one Nb(5) atom. is represented by the CIF card [CIF]
data_Nb12O29
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.741
_cell_length_b   10.741
_cell_length_c   16.013
_cell_angle_alpha   67.306
_cell_angle_beta   67.306
_cell_angle_gamma   20.759
_symmetry_Int_Tables_number   1
_cell_volume   602.313
_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  0.067  0.067  0.399  1.0
  Nb  Nb1  1  0.698  0.698  0.401  1.0
  Nb  Nb2  1  0.880  0.880  0.403  1.0
  Nb  Nb3  1  0.144  0.144  0.129  1.0
  Nb  Nb4  1  0.776  0.776  0.133  1.0
  Nb  Nb5  1  0.960  0.960  0.131  1.0
  Nb  Nb6  1  0.933  0.933  0.601  1.0
  Nb  Nb7  1  0.302  0.302  0.599  1.0
  Nb  Nb8  1  0.120  0.120  0.597  1.0
  Nb  Nb9  1  0.856  0.856  0.871  1.0
  Nb  Nb10  1  0.224  0.224  0.867  1.0
  Nb  Nb11  1  0.040  0.040  0.869  1.0
  O  O12  1  0.000  0.000  0.000  1.0
  O  O13  1  0.166  0.166  0.428  1.0
  O  O14  1  0.367  0.367  0.442  1.0
  O  O15  1  0.587  0.587  0.414  1.0
  O  O16  1  0.781  0.781  0.416  1.0
  O  O17  1  0.970  0.970  0.437  1.0
  O  O18  1  0.100  0.100  0.276  1.0
  O  O19  1  0.729  0.729  0.278  1.0
  O  O20  1  0.922  0.922  0.282  1.0
  O  O21  1  0.055  0.055  0.135  1.0
  O  O22  1  0.248  0.248  0.141  1.0
  O  O23  1  0.454  0.454  0.149  1.0
  O  O24  1  0.666  0.666  0.139  1.0
  O  O25  1  0.861  0.861  0.139  1.0
  O  O26  1  0.188  0.188  0.999  1.0
  O  O27  1  0.834  0.834  0.572  1.0
  O  O28  1  0.633  0.633  0.558  1.0
  O  O29  1  0.413  0.413  0.586  1.0
  O  O30  1  0.219  0.219  0.584  1.0
  O  O31  1  0.030  0.030  0.563  1.0
  O  O32  1  0.900  0.900  0.724  1.0
  O  O33  1  0.271  0.271  0.722  1.0
  O  O34  1  0.078  0.078  0.718  1.0
  O  O35  1  0.945  0.945  0.865  1.0
  O  O36  1  0.752  0.752  0.859  1.0
  O  O37  1  0.546  0.546  0.851  1.0
  O  O38  1  0.334  0.334  0.861  1.0
  O  O39  1  0.139  0.139  0.861  1.0
  O  O40  1  0.812  0.812  0.001  1.0
[/CIF]
.