The material structure described by NaNb13O33 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a square co-planar geometry to four equivalent O(17) atoms. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(8) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Nb site, Nb(2) is bonded to one O(11), one O(12), one O(5), one O(8), and two equivalent O(6) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 2-17°. In the third Nb site, Nb(3) is bonded to one O(10), one O(3), one O(5), one O(7), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-33°. In the fourth Nb site, Nb(4) is bonded to one O(1), one O(4), one O(7), one O(9), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-33°. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to one O(11), one O(14), one O(15), one O(17), and two equivalent O(16) atoms. In the sixth Nb site, Nb(6) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(15), one O(16), and two equivalent O(14) atoms. In the seventh Nb site, Nb(7) is bonded in a 6-coordinate geometry to one O(12), one O(14), one O(17), one O(9), and two equivalent O(13) atoms. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Nb(1) and one Nb(4) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(3) and two equivalent Nb(4) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(4) and two equivalent Nb(3) 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 linear geometry to two equivalent Nb(2) atoms. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(3) and one Nb(4) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(4) and one Nb(7) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Nb(3) and one Nb(6) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Nb(2) and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a linear geometry to one Nb(2) and one Nb(7) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Nb(6) and two equivalent Nb(7) atoms. In the fourteenth O site, O(14) is bonded to one Nb(5), one Nb(7), and two equivalent Nb(6) atoms to form distorted ONb4 trigonal pyramids that share corners with two equivalent O(14)Nb4 trigonal pyramids and  an edgeedge with one O(17)Na2Nb2 tetrahedra. In the fifteenth O site, O(15) is bonded in a linear geometry to one Nb(5) and one Nb(6) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Nb(6) and two equivalent Nb(5) atoms. In the seventeenth O site, O(17) is bonded to two equivalent Na(1), one Nb(5), and one Nb(7) atom to form ONa2Nb2 tetrahedra that share corners with four equivalent O(17)Na2Nb2 tetrahedra,  an edgeedge with one O(17)Na2Nb2 tetrahedra, and  an edgeedge with one O(14)Nb4 trigonal pyramid. is represented by the CIF card [CIF]
data_NaNb13O33
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.851
_cell_length_b   11.531
_cell_length_c   15.577
_cell_angle_alpha   91.539
_cell_angle_beta   89.999
_cell_angle_gamma   99.612
_symmetry_Int_Tables_number   1
_cell_volume   681.828
_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  0.500  1.000  0.500  1.0
  Nb  Nb1  1  0.000  0.000  1.000  1.0
  Nb  Nb2  1  0.070  0.140  0.229  1.0
  Nb  Nb3  1  0.930  0.860  0.771  1.0
  Nb  Nb4  1  0.225  0.449  0.137  1.0
  Nb  Nb5  1  0.775  0.551  0.863  1.0
  Nb  Nb6  1  0.155  0.311  0.905  1.0
  Nb  Nb7  1  0.845  0.689  0.095  1.0
  Nb  Nb8  1  0.137  0.273  0.469  1.0
  Nb  Nb9  1  0.863  0.727  0.531  1.0
  Nb  Nb10  1  0.292  0.585  0.374  1.0
  Nb  Nb11  1  0.708  0.415  0.626  1.0
  Nb  Nb12  1  0.087  0.174  0.676  1.0
  Nb  Nb13  1  0.913  0.826  0.324  1.0
  O  O14  1  0.082  0.164  0.951  1.0
  O  O15  1  0.918  0.836  0.049  1.0
  O  O16  1  0.500  0.000  1.000  1.0
  O  O17  1  0.320  0.640  0.100  1.0
  O  O18  1  0.680  0.360  0.900  1.0
  O  O19  1  0.251  0.501  0.863  1.0
  O  O20  1  0.749  0.499  0.137  1.0
  O  O21  1  0.153  0.306  0.195  1.0
  O  O22  1  0.847  0.694  0.805  1.0
  O  O23  1  0.429  0.859  0.753  1.0
  O  O24  1  0.571  0.141  0.247  1.0
  O  O25  1  0.195  0.390  0.026  1.0
  O  O26  1  0.805  0.610  0.974  1.0
  O  O27  1  0.035  0.070  0.120  1.0
  O  O28  1  0.965  0.930  0.880  1.0
  O  O29  1  0.129  0.258  0.787  1.0
  O  O30  1  0.871  0.742  0.213  1.0
  O  O31  1  0.267  0.534  0.264  1.0
  O  O32  1  0.733  0.466  0.736  1.0
  O  O33  1  0.099  0.198  0.366  1.0
  O  O34  1  0.901  0.802  0.634  1.0
  O  O35  1  0.011  0.023  0.709  1.0
  O  O36  1  0.989  0.977  0.291  1.0
  O  O37  1  0.390  0.780  0.337  1.0
  O  O38  1  0.610  0.220  0.663  1.0
  O  O39  1  0.181  0.363  0.611  1.0
  O  O40  1  0.819  0.637  0.389  1.0
  O  O41  1  0.223  0.445  0.431  1.0
  O  O42  1  0.777  0.555  0.569  1.0
  O  O43  1  0.347  0.695  0.503  1.0
  O  O44  1  0.653  0.305  0.497  1.0
  O  O45  1  0.068  0.137  0.545  1.0
  O  O46  1  0.932  0.863  0.455  1.0
[/CIF]
.
The material structure described by NaNb13O33 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a square co-planar geometry to four equivalent O(17) atoms. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(8) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Nb site, Nb(2) is bonded to one O(11), one O(12), one O(5), one O(8), and two equivalent O(6) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 2-17°. In the third Nb site, Nb(3) is bonded to one O(10), one O(3), one O(5), one O(7), and two equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-33°. In the fourth Nb site, Nb(4) is bonded to one O(1), one O(4), one O(7), one O(9), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-33°. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to one O(11), one O(14), one O(15), one O(17), and two equivalent O(16) atoms. In the sixth Nb site, Nb(6) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(15), one O(16), and two equivalent O(14) atoms. In the seventh Nb site, Nb(7) is bonded in a 6-coordinate geometry to one O(12), one O(14), one O(17), one O(9), and two equivalent O(13) atoms. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Nb(1) and one Nb(4) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(3) and two equivalent Nb(4) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(4) and two equivalent Nb(3) 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 linear geometry to two equivalent Nb(2) atoms. In the seventh O site, O(7) is bonded in a linear geometry to one Nb(3) and one Nb(4) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(4) and one Nb(7) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Nb(3) and one Nb(6) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Nb(2) and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a linear geometry to one Nb(2) and one Nb(7) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Nb(6) and two equivalent Nb(7) atoms. In the fourteenth O site, O(14) is bonded to one Nb(5), one Nb(7), and two equivalent Nb(6) atoms to form distorted ONb4 trigonal pyramids that share corners with two equivalent O(14)Nb4 trigonal pyramids and  an edgeedge with one O(17)Na2Nb2 tetrahedra. In the fifteenth O site, O(15) is bonded in a linear geometry to one Nb(5) and one Nb(6) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Nb(6) and two equivalent Nb(5) atoms. In the seventeenth O site, O(17) is bonded to two equivalent Na(1), one Nb(5), and one Nb(7) atom to form ONa2Nb2 tetrahedra that share corners with four equivalent O(17)Na2Nb2 tetrahedra,  an edgeedge with one O(17)Na2Nb2 tetrahedra, and  an edgeedge with one O(14)Nb4 trigonal pyramid. is represented by the CIF card [CIF]
data_NaNb13O33
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.851
_cell_length_b   11.531
_cell_length_c   15.577
_cell_angle_alpha   91.539
_cell_angle_beta   89.999
_cell_angle_gamma   99.612
_symmetry_Int_Tables_number   1
_cell_volume   681.828
_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  0.500  1.000  0.500  1.0
  Nb  Nb1  1  0.000  0.000  1.000  1.0
  Nb  Nb2  1  0.070  0.140  0.229  1.0
  Nb  Nb3  1  0.930  0.860  0.771  1.0
  Nb  Nb4  1  0.225  0.449  0.137  1.0
  Nb  Nb5  1  0.775  0.551  0.863  1.0
  Nb  Nb6  1  0.155  0.311  0.905  1.0
  Nb  Nb7  1  0.845  0.689  0.095  1.0
  Nb  Nb8  1  0.137  0.273  0.469  1.0
  Nb  Nb9  1  0.863  0.727  0.531  1.0
  Nb  Nb10  1  0.292  0.585  0.374  1.0
  Nb  Nb11  1  0.708  0.415  0.626  1.0
  Nb  Nb12  1  0.087  0.174  0.676  1.0
  Nb  Nb13  1  0.913  0.826  0.324  1.0
  O  O14  1  0.082  0.164  0.951  1.0
  O  O15  1  0.918  0.836  0.049  1.0
  O  O16  1  0.500  0.000  1.000  1.0
  O  O17  1  0.320  0.640  0.100  1.0
  O  O18  1  0.680  0.360  0.900  1.0
  O  O19  1  0.251  0.501  0.863  1.0
  O  O20  1  0.749  0.499  0.137  1.0
  O  O21  1  0.153  0.306  0.195  1.0
  O  O22  1  0.847  0.694  0.805  1.0
  O  O23  1  0.429  0.859  0.753  1.0
  O  O24  1  0.571  0.141  0.247  1.0
  O  O25  1  0.195  0.390  0.026  1.0
  O  O26  1  0.805  0.610  0.974  1.0
  O  O27  1  0.035  0.070  0.120  1.0
  O  O28  1  0.965  0.930  0.880  1.0
  O  O29  1  0.129  0.258  0.787  1.0
  O  O30  1  0.871  0.742  0.213  1.0
  O  O31  1  0.267  0.534  0.264  1.0
  O  O32  1  0.733  0.466  0.736  1.0
  O  O33  1  0.099  0.198  0.366  1.0
  O  O34  1  0.901  0.802  0.634  1.0
  O  O35  1  0.011  0.023  0.709  1.0
  O  O36  1  0.989  0.977  0.291  1.0
  O  O37  1  0.390  0.780  0.337  1.0
  O  O38  1  0.610  0.220  0.663  1.0
  O  O39  1  0.181  0.363  0.611  1.0
  O  O40  1  0.819  0.637  0.389  1.0
  O  O41  1  0.223  0.445  0.431  1.0
  O  O42  1  0.777  0.555  0.569  1.0
  O  O43  1  0.347  0.695  0.503  1.0
  O  O44  1  0.653  0.305  0.497  1.0
  O  O45  1  0.068  0.137  0.545  1.0
  O  O46  1  0.932  0.863  0.455  1.0
[/CIF]
.