The compound described by Na2Bi4O7 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(1), and two equivalent O(3) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(2) atoms. In the second Bi site, Bi(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), one Bi(1), and one Bi(2) atom to form a mixture of edge and corner-sharing ONa2Bi2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Bi(2) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Na(1) and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing ONa2Bi2 tetrahedra. is represented by the CIF file [CIF]
data_Na2Bi4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.214
_cell_length_b   10.214
_cell_length_c   5.878
_cell_angle_alpha   74.761
_cell_angle_beta   74.760
_cell_angle_gamma   114.745
_symmetry_Int_Tables_number   1
_cell_volume   486.265
_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  0.485  0.656  0.432  1.0
  Na  Na1  1  0.344  0.515  0.068  1.0
  Na  Na2  1  0.656  0.485  0.932  1.0
  Na  Na3  1  0.515  0.344  0.568  1.0
  Bi  Bi4  1  0.612  0.118  0.168  1.0
  Bi  Bi5  1  0.268  0.128  0.239  1.0
  Bi  Bi6  1  0.118  0.612  0.668  1.0
  Bi  Bi7  1  0.128  0.268  0.739  1.0
  Bi  Bi8  1  0.872  0.732  0.261  1.0
  Bi  Bi9  1  0.882  0.388  0.332  1.0
  Bi  Bi10  1  0.732  0.872  0.761  1.0
  Bi  Bi11  1  0.388  0.882  0.832  1.0
  O  O12  1  0.495  0.216  0.968  1.0
  O  O13  1  0.372  0.993  0.454  1.0
  O  O14  1  0.711  0.678  0.095  1.0
  O  O15  1  0.681  0.319  0.250  1.0
  O  O16  1  0.216  0.495  0.468  1.0
  O  O17  1  0.993  0.372  0.954  1.0
  O  O18  1  0.322  0.289  0.405  1.0
  O  O19  1  0.678  0.711  0.595  1.0
  O  O20  1  0.007  0.628  0.046  1.0
  O  O21  1  0.784  0.505  0.532  1.0
  O  O22  1  0.319  0.681  0.750  1.0
  O  O23  1  0.289  0.322  0.905  1.0
  O  O24  1  0.628  0.007  0.546  1.0
  O  O25  1  0.505  0.784  0.032  1.0
[/CIF]
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The compound described by Na2Bi4O7 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(1), and two equivalent O(3) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(2) atoms. In the second Bi site, Bi(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), one Bi(1), and one Bi(2) atom to form a mixture of edge and corner-sharing ONa2Bi2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Bi(2) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Na(1) and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing ONa2Bi2 tetrahedra. is represented by the CIF file [CIF]
data_Na2Bi4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.214
_cell_length_b   10.214
_cell_length_c   5.878
_cell_angle_alpha   74.761
_cell_angle_beta   74.760
_cell_angle_gamma   114.745
_symmetry_Int_Tables_number   1
_cell_volume   486.265
_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  0.485  0.656  0.432  1.0
  Na  Na1  1  0.344  0.515  0.068  1.0
  Na  Na2  1  0.656  0.485  0.932  1.0
  Na  Na3  1  0.515  0.344  0.568  1.0
  Bi  Bi4  1  0.612  0.118  0.168  1.0
  Bi  Bi5  1  0.268  0.128  0.239  1.0
  Bi  Bi6  1  0.118  0.612  0.668  1.0
  Bi  Bi7  1  0.128  0.268  0.739  1.0
  Bi  Bi8  1  0.872  0.732  0.261  1.0
  Bi  Bi9  1  0.882  0.388  0.332  1.0
  Bi  Bi10  1  0.732  0.872  0.761  1.0
  Bi  Bi11  1  0.388  0.882  0.832  1.0
  O  O12  1  0.495  0.216  0.968  1.0
  O  O13  1  0.372  0.993  0.454  1.0
  O  O14  1  0.711  0.678  0.095  1.0
  O  O15  1  0.681  0.319  0.250  1.0
  O  O16  1  0.216  0.495  0.468  1.0
  O  O17  1  0.993  0.372  0.954  1.0
  O  O18  1  0.322  0.289  0.405  1.0
  O  O19  1  0.678  0.711  0.595  1.0
  O  O20  1  0.007  0.628  0.046  1.0
  O  O21  1  0.784  0.505  0.532  1.0
  O  O22  1  0.319  0.681  0.750  1.0
  O  O23  1  0.289  0.322  0.905  1.0
  O  O24  1  0.628  0.007  0.546  1.0
  O  O25  1  0.505  0.784  0.032  1.0
[/CIF]
.