The material described by Na2B4O17 crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 2-coordinate geometry to two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second Na site, Na(2) is bonded in a hexagonal planar geometry to two equivalent O(4), two equivalent O(6), and two equivalent O(9) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. There are nine inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Na(2) and one O(7) atom. In the second O site, O(5) is bonded in a bent 120 degrees geometry to one Na(1) and one B(2) atom. In the third O site, O(6) is bonded in a bent 120 degrees geometry to one Na(2) and one O(6) atom. In the fourth O site, O(7) is bonded in a bent 120 degrees geometry to one Na(1) and one O(4) atom. In the fifth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Na(1) and one O(9) atom. In the sixth O site, O(9) is bonded in a bent 150 degrees geometry to one Na(2) and one O(8) atom. In the seventh O site, O(1) is bonded in an L-shaped geometry to two equivalent B(1) atoms. In the eighth O site, O(2) is bonded in a water-like geometry to one B(1) and one B(2) atom. In the ninth O site, O(3) is bonded in a bent 120 degrees geometry to one B(1) and one B(2) atom. is represented by the CIF file [CIF]
data_Na2B4O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.144
_cell_length_b   8.144
_cell_length_c   12.936
_cell_angle_alpha   81.105
_cell_angle_beta   81.105
_cell_angle_gamma   101.431
_symmetry_Int_Tables_number   1
_cell_volume   815.416
_cell_formula_units_Z   2
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  0.000  0.500  1.0
  Na  Na1  1  0.000  0.500  0.000  1.0
  Na  Na2  1  0.500  0.500  0.750  1.0
  Na  Na3  1  0.500  0.500  0.250  1.0
  B  B4  1  0.961  0.235  0.722  1.0
  B  B5  1  0.765  0.039  0.778  1.0
  B  B6  1  0.039  0.765  0.278  1.0
  B  B7  1  0.235  0.961  0.222  1.0
  B  B8  1  0.821  0.222  0.899  1.0
  B  B9  1  0.778  0.179  0.601  1.0
  B  B10  1  0.179  0.778  0.101  1.0
  B  B11  1  0.222  0.821  0.399  1.0
  O  O12  1  0.944  0.056  0.750  1.0
  O  O13  1  0.056  0.944  0.250  1.0
  O  O14  1  0.956  0.319  0.807  1.0
  O  O15  1  0.681  0.044  0.693  1.0
  O  O16  1  0.044  0.681  0.193  1.0
  O  O17  1  0.319  0.956  0.307  1.0
  O  O18  1  0.921  0.293  0.625  1.0
  O  O19  1  0.707  0.079  0.875  1.0
  O  O20  1  0.079  0.707  0.375  1.0
  O  O21  1  0.293  0.921  0.125  1.0
  O  O22  1  0.309  0.242  0.695  1.0
  O  O23  1  0.758  0.691  0.805  1.0
  O  O24  1  0.691  0.758  0.305  1.0
  O  O25  1  0.242  0.309  0.195  1.0
  O  O26  1  0.803  0.277  0.989  1.0
  O  O27  1  0.723  0.197  0.511  1.0
  O  O28  1  0.197  0.723  0.011  1.0
  O  O29  1  0.277  0.803  0.489  1.0
  O  O30  1  0.461  0.536  0.969  1.0
  O  O31  1  0.464  0.539  0.531  1.0
  O  O32  1  0.539  0.464  0.031  1.0
  O  O33  1  0.536  0.461  0.469  1.0
  O  O34  1  0.341  0.103  0.683  1.0
  O  O35  1  0.897  0.659  0.817  1.0
  O  O36  1  0.659  0.897  0.317  1.0
  O  O37  1  0.103  0.341  0.183  1.0
  O  O38  1  0.841  0.800  0.016  1.0
  O  O39  1  0.200  0.159  0.484  1.0
  O  O40  1  0.159  0.200  0.984  1.0
  O  O41  1  0.800  0.841  0.516  1.0
  O  O42  1  0.774  0.710  0.584  1.0
  O  O43  1  0.290  0.226  0.916  1.0
  O  O44  1  0.226  0.290  0.416  1.0
  O  O45  1  0.710  0.774  0.084  1.0
[/CIF]
.
The material described by Na2B4O17 crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 2-coordinate geometry to two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second Na site, Na(2) is bonded in a hexagonal planar geometry to two equivalent O(4), two equivalent O(6), and two equivalent O(9) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. There are nine inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Na(2) and one O(7) atom. In the second O site, O(5) is bonded in a bent 120 degrees geometry to one Na(1) and one B(2) atom. In the third O site, O(6) is bonded in a bent 120 degrees geometry to one Na(2) and one O(6) atom. In the fourth O site, O(7) is bonded in a bent 120 degrees geometry to one Na(1) and one O(4) atom. In the fifth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Na(1) and one O(9) atom. In the sixth O site, O(9) is bonded in a bent 150 degrees geometry to one Na(2) and one O(8) atom. In the seventh O site, O(1) is bonded in an L-shaped geometry to two equivalent B(1) atoms. In the eighth O site, O(2) is bonded in a water-like geometry to one B(1) and one B(2) atom. In the ninth O site, O(3) is bonded in a bent 120 degrees geometry to one B(1) and one B(2) atom. is represented by the CIF file [CIF]
data_Na2B4O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.144
_cell_length_b   8.144
_cell_length_c   12.936
_cell_angle_alpha   81.105
_cell_angle_beta   81.105
_cell_angle_gamma   101.431
_symmetry_Int_Tables_number   1
_cell_volume   815.416
_cell_formula_units_Z   2
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  0.000  0.500  1.0
  Na  Na1  1  0.000  0.500  0.000  1.0
  Na  Na2  1  0.500  0.500  0.750  1.0
  Na  Na3  1  0.500  0.500  0.250  1.0
  B  B4  1  0.961  0.235  0.722  1.0
  B  B5  1  0.765  0.039  0.778  1.0
  B  B6  1  0.039  0.765  0.278  1.0
  B  B7  1  0.235  0.961  0.222  1.0
  B  B8  1  0.821  0.222  0.899  1.0
  B  B9  1  0.778  0.179  0.601  1.0
  B  B10  1  0.179  0.778  0.101  1.0
  B  B11  1  0.222  0.821  0.399  1.0
  O  O12  1  0.944  0.056  0.750  1.0
  O  O13  1  0.056  0.944  0.250  1.0
  O  O14  1  0.956  0.319  0.807  1.0
  O  O15  1  0.681  0.044  0.693  1.0
  O  O16  1  0.044  0.681  0.193  1.0
  O  O17  1  0.319  0.956  0.307  1.0
  O  O18  1  0.921  0.293  0.625  1.0
  O  O19  1  0.707  0.079  0.875  1.0
  O  O20  1  0.079  0.707  0.375  1.0
  O  O21  1  0.293  0.921  0.125  1.0
  O  O22  1  0.309  0.242  0.695  1.0
  O  O23  1  0.758  0.691  0.805  1.0
  O  O24  1  0.691  0.758  0.305  1.0
  O  O25  1  0.242  0.309  0.195  1.0
  O  O26  1  0.803  0.277  0.989  1.0
  O  O27  1  0.723  0.197  0.511  1.0
  O  O28  1  0.197  0.723  0.011  1.0
  O  O29  1  0.277  0.803  0.489  1.0
  O  O30  1  0.461  0.536  0.969  1.0
  O  O31  1  0.464  0.539  0.531  1.0
  O  O32  1  0.539  0.464  0.031  1.0
  O  O33  1  0.536  0.461  0.469  1.0
  O  O34  1  0.341  0.103  0.683  1.0
  O  O35  1  0.897  0.659  0.817  1.0
  O  O36  1  0.659  0.897  0.317  1.0
  O  O37  1  0.103  0.341  0.183  1.0
  O  O38  1  0.841  0.800  0.016  1.0
  O  O39  1  0.200  0.159  0.484  1.0
  O  O40  1  0.159  0.200  0.984  1.0
  O  O41  1  0.800  0.841  0.516  1.0
  O  O42  1  0.774  0.710  0.584  1.0
  O  O43  1  0.290  0.226  0.916  1.0
  O  O44  1  0.226  0.290  0.416  1.0
  O  O45  1  0.710  0.774  0.084  1.0
[/CIF]
.