The compound described by Na2SeO3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing NaO6 octahedra. The corner-sharing octahedral tilt angles range from 15-33°. In the second Na site, Na(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing NaO6 octahedra. The corner-sharing octahedral tilt angles range from 15-33°. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Na(2), and one Se(1) atom to form ONa3Se trigonal pyramids that share corners with two equivalent O(3)Na5Se octahedra, corners with five equivalent O(2)Na4Se trigonal bipyramids, corners with two equivalent O(1)Na3Se trigonal pyramids, edges with three equivalent O(3)Na5Se octahedra, and  an edgeedge with one O(2)Na4Se trigonal bipyramid. The corner-sharing octahedral tilt angles range from 82-90°. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and one Se(1) atom to form distorted ONa4Se trigonal bipyramids that share  a cornercorner with one O(3)Na5Se octahedra, corners with four equivalent O(2)Na4Se trigonal bipyramids, corners with five equivalent O(1)Na3Se trigonal pyramids, edges with five equivalent O(3)Na5Se octahedra, and  an edgeedge with one O(1)Na3Se trigonal pyramid. The corner-sharing octahedral tilt angles are 22°. In the third O site, O(3) is bonded to two equivalent Na(2), three equivalent Na(1), and one Se(1) atom to form distorted ONa5Se octahedra that share corners with four equivalent O(3)Na5Se octahedra,  a cornercorner with one O(2)Na4Se trigonal bipyramid, corners with two equivalent O(1)Na3Se trigonal pyramids, edges with two equivalent O(3)Na5Se octahedra, edges with five equivalent O(2)Na4Se trigonal bipyramids, and edges with three equivalent O(1)Na3Se trigonal pyramids. The corner-sharing octahedral tilt angles range from 2-15°. is represented by the CIF card [CIF]
data_Na2SeO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.929
_cell_length_b   4.839
_cell_length_c   6.789
_cell_angle_alpha   91.033
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   326.131
_cell_formula_units_Z   4
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  0.413  0.259  0.851  1.0
  Na  Na1  1  0.247  0.756  0.091  1.0
  Na  Na2  1  0.253  0.756  0.591  1.0
  Na  Na3  1  0.753  0.244  0.909  1.0
  Na  Na4  1  0.587  0.741  0.149  1.0
  Na  Na5  1  0.087  0.259  0.351  1.0
  Na  Na6  1  0.913  0.741  0.649  1.0
  Na  Na7  1  0.747  0.244  0.409  1.0
  Se  Se8  1  0.916  0.777  0.186  1.0
  Se  Se9  1  0.416  0.223  0.314  1.0
  Se  Se10  1  0.084  0.223  0.814  1.0
  Se  Se11  1  0.584  0.777  0.686  1.0
  O  O12  1  0.599  0.126  0.661  1.0
  O  O13  1  0.099  0.874  0.839  1.0
  O  O14  1  0.401  0.874  0.339  1.0
  O  O15  1  0.901  0.126  0.161  1.0
  O  O16  1  0.711  0.721  0.852  1.0
  O  O17  1  0.211  0.279  0.648  1.0
  O  O18  1  0.289  0.279  0.148  1.0
  O  O19  1  0.789  0.721  0.352  1.0
  O  O20  1  0.442  0.753  0.831  1.0
  O  O21  1  0.058  0.753  0.331  1.0
  O  O22  1  0.558  0.247  0.169  1.0
  O  O23  1  0.942  0.247  0.669  1.0
[/CIF]
.
The compound described by Na2SeO3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing NaO6 octahedra. The corner-sharing octahedral tilt angles range from 15-33°. In the second Na site, Na(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing NaO6 octahedra. The corner-sharing octahedral tilt angles range from 15-33°. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Na(2), and one Se(1) atom to form ONa3Se trigonal pyramids that share corners with two equivalent O(3)Na5Se octahedra, corners with five equivalent O(2)Na4Se trigonal bipyramids, corners with two equivalent O(1)Na3Se trigonal pyramids, edges with three equivalent O(3)Na5Se octahedra, and  an edgeedge with one O(2)Na4Se trigonal bipyramid. The corner-sharing octahedral tilt angles range from 82-90°. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and one Se(1) atom to form distorted ONa4Se trigonal bipyramids that share  a cornercorner with one O(3)Na5Se octahedra, corners with four equivalent O(2)Na4Se trigonal bipyramids, corners with five equivalent O(1)Na3Se trigonal pyramids, edges with five equivalent O(3)Na5Se octahedra, and  an edgeedge with one O(1)Na3Se trigonal pyramid. The corner-sharing octahedral tilt angles are 22°. In the third O site, O(3) is bonded to two equivalent Na(2), three equivalent Na(1), and one Se(1) atom to form distorted ONa5Se octahedra that share corners with four equivalent O(3)Na5Se octahedra,  a cornercorner with one O(2)Na4Se trigonal bipyramid, corners with two equivalent O(1)Na3Se trigonal pyramids, edges with two equivalent O(3)Na5Se octahedra, edges with five equivalent O(2)Na4Se trigonal bipyramids, and edges with three equivalent O(1)Na3Se trigonal pyramids. The corner-sharing octahedral tilt angles range from 2-15°. is represented by the CIF card [CIF]
data_Na2SeO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.929
_cell_length_b   4.839
_cell_length_c   6.789
_cell_angle_alpha   91.033
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   326.131
_cell_formula_units_Z   4
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  0.413  0.259  0.851  1.0
  Na  Na1  1  0.247  0.756  0.091  1.0
  Na  Na2  1  0.253  0.756  0.591  1.0
  Na  Na3  1  0.753  0.244  0.909  1.0
  Na  Na4  1  0.587  0.741  0.149  1.0
  Na  Na5  1  0.087  0.259  0.351  1.0
  Na  Na6  1  0.913  0.741  0.649  1.0
  Na  Na7  1  0.747  0.244  0.409  1.0
  Se  Se8  1  0.916  0.777  0.186  1.0
  Se  Se9  1  0.416  0.223  0.314  1.0
  Se  Se10  1  0.084  0.223  0.814  1.0
  Se  Se11  1  0.584  0.777  0.686  1.0
  O  O12  1  0.599  0.126  0.661  1.0
  O  O13  1  0.099  0.874  0.839  1.0
  O  O14  1  0.401  0.874  0.339  1.0
  O  O15  1  0.901  0.126  0.161  1.0
  O  O16  1  0.711  0.721  0.852  1.0
  O  O17  1  0.211  0.279  0.648  1.0
  O  O18  1  0.289  0.279  0.148  1.0
  O  O19  1  0.789  0.721  0.352  1.0
  O  O20  1  0.442  0.753  0.831  1.0
  O  O21  1  0.058  0.753  0.331  1.0
  O  O22  1  0.558  0.247  0.169  1.0
  O  O23  1  0.942  0.247  0.669  1.0
[/CIF]
.