The structure described by Na3Sb3(AsO7)2 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 two equivalent O(1), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form NaO8 hexagonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Sb(2)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(7), and two equivalent O(4) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(3), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, and edges with two equivalent Na(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-48°. In the second Sb site, Sb(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form SbO6 octahedra that share corners with four equivalent Sb(1)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, and edges with two equivalent Na(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 41-48°. As(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form AsO4 tetrahedra that share  a cornercorner with one Na(1)O8 hexagonal bipyramid,  a cornercorner with one Sb(2)O6 octahedra, and corners with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-58°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Na(1) and two equivalent Sb(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(2), one Sb(2), and one As(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Na(2), one Sb(1), and one As(1) atom. In the fourth O site, O(4) is bonded to one Na(1), two equivalent Na(2), and one As(1) atom to form a mixture of distorted corner and edge-sharing ONa3As tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Na(2), one Sb(1), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Sb(1), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Sb(1), and one Sb(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3Sb3(AsO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.279
_cell_length_b   6.464
_cell_length_c   12.536
_cell_angle_alpha   72.635
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   563.025
_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  0.000  0.000  0.000  1.0
  Na  Na1  1  0.712  0.538  0.567  1.0
  Na  Na2  1  0.288  0.462  0.433  1.0
  Na  Na3  1  0.788  0.538  0.067  1.0
  Na  Na4  1  0.500  0.000  0.500  1.0
  Na  Na5  1  0.212  0.462  0.933  1.0
  Sb  Sb6  1  0.240  0.023  0.747  1.0
  Sb  Sb7  1  0.260  0.023  0.247  1.0
  Sb  Sb8  1  0.760  0.977  0.253  1.0
  Sb  Sb9  1  0.740  0.977  0.753  1.0
  Sb  Sb10  1  0.000  0.000  0.500  1.0
  Sb  Sb11  1  0.500  0.000  0.000  1.0
  As  As12  1  0.765  0.416  0.339  1.0
  As  As13  1  0.735  0.416  0.839  1.0
  As  As14  1  0.265  0.584  0.161  1.0
  As  As15  1  0.235  0.584  0.661  1.0
  O  O16  1  0.994  0.933  0.802  1.0
  O  O17  1  0.531  0.317  0.907  1.0
  O  O18  1  0.274  0.705  0.762  1.0
  O  O19  1  0.095  0.611  0.070  1.0
  O  O20  1  0.811  0.671  0.256  1.0
  O  O21  1  0.797  0.034  0.594  1.0
  O  O22  1  0.969  0.317  0.407  1.0
  O  O23  1  0.031  0.683  0.593  1.0
  O  O24  1  0.595  0.389  0.430  1.0
  O  O25  1  0.811  0.899  0.415  1.0
  O  O26  1  0.311  0.329  0.244  1.0
  O  O27  1  0.689  0.671  0.756  1.0
  O  O28  1  0.774  0.295  0.738  1.0
  O  O29  1  0.905  0.389  0.930  1.0
  O  O30  1  0.006  0.067  0.198  1.0
  O  O31  1  0.469  0.683  0.093  1.0
  O  O32  1  0.203  0.966  0.406  1.0
  O  O33  1  0.494  0.067  0.698  1.0
  O  O34  1  0.689  0.899  0.915  1.0
  O  O35  1  0.405  0.611  0.570  1.0
  O  O36  1  0.226  0.705  0.262  1.0
  O  O37  1  0.311  0.101  0.085  1.0
  O  O38  1  0.726  0.295  0.238  1.0
  O  O39  1  0.297  0.966  0.906  1.0
  O  O40  1  0.506  0.933  0.302  1.0
  O  O41  1  0.703  0.034  0.094  1.0
  O  O42  1  0.189  0.101  0.585  1.0
  O  O43  1  0.189  0.329  0.744  1.0
[/CIF]
.
The structure described by Na3Sb3(AsO7)2 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 two equivalent O(1), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form NaO8 hexagonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Sb(2)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(7), and two equivalent O(4) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(3), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, and edges with two equivalent Na(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-48°. In the second Sb site, Sb(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form SbO6 octahedra that share corners with four equivalent Sb(1)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, and edges with two equivalent Na(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 41-48°. As(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form AsO4 tetrahedra that share  a cornercorner with one Na(1)O8 hexagonal bipyramid,  a cornercorner with one Sb(2)O6 octahedra, and corners with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-58°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Na(1) and two equivalent Sb(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(2), one Sb(2), and one As(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Na(2), one Sb(1), and one As(1) atom. In the fourth O site, O(4) is bonded to one Na(1), two equivalent Na(2), and one As(1) atom to form a mixture of distorted corner and edge-sharing ONa3As tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Na(2), one Sb(1), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Sb(1), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Sb(1), and one Sb(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3Sb3(AsO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.279
_cell_length_b   6.464
_cell_length_c   12.536
_cell_angle_alpha   72.635
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   563.025
_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  0.000  0.000  0.000  1.0
  Na  Na1  1  0.712  0.538  0.567  1.0
  Na  Na2  1  0.288  0.462  0.433  1.0
  Na  Na3  1  0.788  0.538  0.067  1.0
  Na  Na4  1  0.500  0.000  0.500  1.0
  Na  Na5  1  0.212  0.462  0.933  1.0
  Sb  Sb6  1  0.240  0.023  0.747  1.0
  Sb  Sb7  1  0.260  0.023  0.247  1.0
  Sb  Sb8  1  0.760  0.977  0.253  1.0
  Sb  Sb9  1  0.740  0.977  0.753  1.0
  Sb  Sb10  1  0.000  0.000  0.500  1.0
  Sb  Sb11  1  0.500  0.000  0.000  1.0
  As  As12  1  0.765  0.416  0.339  1.0
  As  As13  1  0.735  0.416  0.839  1.0
  As  As14  1  0.265  0.584  0.161  1.0
  As  As15  1  0.235  0.584  0.661  1.0
  O  O16  1  0.994  0.933  0.802  1.0
  O  O17  1  0.531  0.317  0.907  1.0
  O  O18  1  0.274  0.705  0.762  1.0
  O  O19  1  0.095  0.611  0.070  1.0
  O  O20  1  0.811  0.671  0.256  1.0
  O  O21  1  0.797  0.034  0.594  1.0
  O  O22  1  0.969  0.317  0.407  1.0
  O  O23  1  0.031  0.683  0.593  1.0
  O  O24  1  0.595  0.389  0.430  1.0
  O  O25  1  0.811  0.899  0.415  1.0
  O  O26  1  0.311  0.329  0.244  1.0
  O  O27  1  0.689  0.671  0.756  1.0
  O  O28  1  0.774  0.295  0.738  1.0
  O  O29  1  0.905  0.389  0.930  1.0
  O  O30  1  0.006  0.067  0.198  1.0
  O  O31  1  0.469  0.683  0.093  1.0
  O  O32  1  0.203  0.966  0.406  1.0
  O  O33  1  0.494  0.067  0.698  1.0
  O  O34  1  0.689  0.899  0.915  1.0
  O  O35  1  0.405  0.611  0.570  1.0
  O  O36  1  0.226  0.705  0.262  1.0
  O  O37  1  0.311  0.101  0.085  1.0
  O  O38  1  0.726  0.295  0.238  1.0
  O  O39  1  0.297  0.966  0.906  1.0
  O  O40  1  0.506  0.933  0.302  1.0
  O  O41  1  0.703  0.034  0.094  1.0
  O  O42  1  0.189  0.101  0.585  1.0
  O  O43  1  0.189  0.329  0.744  1.0
[/CIF]
.