The compound described by Na6Sn2O7 crystallizes in the monoclinic C2/c space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted NaO5 square pyramids that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Sn(1)O5 square pyramid, corners with three equivalent Na(2)O5 square pyramids, corners with five equivalent Na(3)O5 square pyramids,  an edgeedge with one Na(1)O5 square pyramid,  an edgeedge with one Na(3)O5 square pyramid, edges with two equivalent Na(2)O5 square pyramids, and edges with three equivalent Sn(1)O5 square pyramids. In the second Na site, Na(2) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form distorted NaO5 square pyramids that share  a cornercorner with one Na(2)O5 square pyramid, corners with two equivalent Na(3)O5 square pyramids, corners with three equivalent Na(1)O5 square pyramids, corners with four equivalent Sn(1)O5 square pyramids,  an edgeedge with one Na(2)O5 square pyramid, edges with two equivalent Na(1)O5 square pyramids, edges with two equivalent Na(3)O5 square pyramids, and edges with two equivalent Sn(1)O5 square pyramids. In the third Na site, Na(3) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form NaO5 square pyramids that share corners with two equivalent Na(2)O5 square pyramids, corners with two equivalent Na(3)O5 square pyramids, corners with two equivalent Sn(1)O5 square pyramids, corners with five equivalent Na(1)O5 square pyramids,  an edgeedge with one Na(1)O5 square pyramid,  an edgeedge with one Na(3)O5 square pyramid, edges with two equivalent Na(2)O5 square pyramids, and edges with two equivalent Sn(1)O5 square pyramids. Sn(1) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form distorted SnO5 square pyramids that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Sn(1)O5 square pyramid, corners with two equivalent Na(3)O5 square pyramids, corners with four equivalent Na(2)O5 square pyramids,  an edgeedge with one Sn(1)O5 square pyramid, edges with two equivalent Na(2)O5 square pyramids, edges with two equivalent Na(3)O5 square pyramids, and edges with three equivalent Na(1)O5 square pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), two equivalent Na(1), two equivalent Na(3), and one Sn(1) atom to form distorted ONa5Sn octahedra that share corners with four equivalent O(3)Na4Sn square pyramids, edges with two equivalent O(4)Na4Sn2 octahedra, edges with two equivalent O(1)Na5Sn octahedra, edges with four equivalent O(2)Na4Sn2 octahedra, and edges with two equivalent O(3)Na4Sn square pyramids. In the second O site, O(2) is bonded to one Na(1), one Na(3), two equivalent Na(2), and two equivalent Sn(1) atoms to form ONa4Sn2 octahedra that share corners with three equivalent O(4)Na4Sn2 octahedra, corners with three equivalent O(3)Na4Sn square pyramids,  an edgeedge with one O(4)Na4Sn2 octahedra, edges with two equivalent O(2)Na4Sn2 octahedra, edges with four equivalent O(1)Na5Sn octahedra, and edges with two equivalent O(3)Na4Sn square pyramids. The corner-sharing octahedral tilt angles range from 1-21°. In the third O site, O(3) is bonded to one Na(1), one Na(2), two equivalent Na(3), and one Sn(1) atom to form distorted ONa4Sn square pyramids that share  a cornercorner with one O(4)Na4Sn2 octahedra, corners with three equivalent O(2)Na4Sn2 octahedra, corners with four equivalent O(1)Na5Sn octahedra, corners with two equivalent O(3)Na4Sn square pyramids,  an edgeedge with one O(4)Na4Sn2 octahedra, edges with two equivalent O(2)Na4Sn2 octahedra, and edges with two equivalent O(1)Na5Sn octahedra. The corner-sharing octahedral tilt angles range from 9-93°. In the fourth O site, O(4) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Sn(1) atoms to form ONa4Sn2 octahedra that share corners with six equivalent O(2)Na4Sn2 octahedra, corners with two equivalent O(3)Na4Sn square pyramids, edges with two equivalent O(2)Na4Sn2 octahedra, edges with four equivalent O(1)Na5Sn octahedra, and edges with two equivalent O(3)Na4Sn square pyramids. The corner-sharing octahedral tilt angles range from 1-21°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na6Sn2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.632
_cell_length_b   6.632
_cell_length_c   11.050
_cell_angle_alpha   79.245
_cell_angle_beta   79.245
_cell_angle_gamma   59.974
_symmetry_Int_Tables_number   1
_cell_volume   410.851
_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  0.530  0.326  0.122  1.0
  Na  Na1  1  0.076  0.785  0.097  1.0
  Na  Na2  1  0.326  0.530  0.622  1.0
  Na  Na3  1  0.785  0.076  0.597  1.0
  Na  Na4  1  0.672  0.925  0.381  1.0
  Na  Na5  1  0.925  0.672  0.881  1.0
  Na  Na6  1  0.075  0.328  0.119  1.0
  Na  Na7  1  0.328  0.075  0.619  1.0
  Na  Na8  1  0.215  0.924  0.403  1.0
  Na  Na9  1  0.674  0.470  0.378  1.0
  Na  Na10  1  0.924  0.215  0.903  1.0
  Na  Na11  1  0.470  0.674  0.878  1.0
  Sn  Sn12  1  0.176  0.470  0.374  1.0
  Sn  Sn13  1  0.470  0.176  0.874  1.0
  Sn  Sn14  1  0.530  0.824  0.126  1.0
  Sn  Sn15  1  0.824  0.530  0.626  1.0
  O  O16  1  0.469  0.277  0.459  1.0
  O  O17  1  0.277  0.469  0.959  1.0
  O  O18  1  0.719  0.996  0.003  1.0
  O  O19  1  0.921  0.606  0.258  1.0
  O  O20  1  0.394  0.079  0.242  1.0
  O  O21  1  0.996  0.719  0.503  1.0
  O  O22  1  0.004  0.281  0.497  1.0
  O  O23  1  0.606  0.921  0.758  1.0
  O  O24  1  0.079  0.394  0.742  1.0
  O  O25  1  0.281  0.004  0.997  1.0
  O  O26  1  0.723  0.531  0.041  1.0
  O  O27  1  0.344  0.656  0.250  1.0
  O  O28  1  0.531  0.723  0.541  1.0
  O  O29  1  0.656  0.344  0.750  1.0
[/CIF]
.
The compound described by Na6Sn2O7 crystallizes in the monoclinic C2/c space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted NaO5 square pyramids that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Sn(1)O5 square pyramid, corners with three equivalent Na(2)O5 square pyramids, corners with five equivalent Na(3)O5 square pyramids,  an edgeedge with one Na(1)O5 square pyramid,  an edgeedge with one Na(3)O5 square pyramid, edges with two equivalent Na(2)O5 square pyramids, and edges with three equivalent Sn(1)O5 square pyramids. In the second Na site, Na(2) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form distorted NaO5 square pyramids that share  a cornercorner with one Na(2)O5 square pyramid, corners with two equivalent Na(3)O5 square pyramids, corners with three equivalent Na(1)O5 square pyramids, corners with four equivalent Sn(1)O5 square pyramids,  an edgeedge with one Na(2)O5 square pyramid, edges with two equivalent Na(1)O5 square pyramids, edges with two equivalent Na(3)O5 square pyramids, and edges with two equivalent Sn(1)O5 square pyramids. In the third Na site, Na(3) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form NaO5 square pyramids that share corners with two equivalent Na(2)O5 square pyramids, corners with two equivalent Na(3)O5 square pyramids, corners with two equivalent Sn(1)O5 square pyramids, corners with five equivalent Na(1)O5 square pyramids,  an edgeedge with one Na(1)O5 square pyramid,  an edgeedge with one Na(3)O5 square pyramid, edges with two equivalent Na(2)O5 square pyramids, and edges with two equivalent Sn(1)O5 square pyramids. Sn(1) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form distorted SnO5 square pyramids that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Sn(1)O5 square pyramid, corners with two equivalent Na(3)O5 square pyramids, corners with four equivalent Na(2)O5 square pyramids,  an edgeedge with one Sn(1)O5 square pyramid, edges with two equivalent Na(2)O5 square pyramids, edges with two equivalent Na(3)O5 square pyramids, and edges with three equivalent Na(1)O5 square pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), two equivalent Na(1), two equivalent Na(3), and one Sn(1) atom to form distorted ONa5Sn octahedra that share corners with four equivalent O(3)Na4Sn square pyramids, edges with two equivalent O(4)Na4Sn2 octahedra, edges with two equivalent O(1)Na5Sn octahedra, edges with four equivalent O(2)Na4Sn2 octahedra, and edges with two equivalent O(3)Na4Sn square pyramids. In the second O site, O(2) is bonded to one Na(1), one Na(3), two equivalent Na(2), and two equivalent Sn(1) atoms to form ONa4Sn2 octahedra that share corners with three equivalent O(4)Na4Sn2 octahedra, corners with three equivalent O(3)Na4Sn square pyramids,  an edgeedge with one O(4)Na4Sn2 octahedra, edges with two equivalent O(2)Na4Sn2 octahedra, edges with four equivalent O(1)Na5Sn octahedra, and edges with two equivalent O(3)Na4Sn square pyramids. The corner-sharing octahedral tilt angles range from 1-21°. In the third O site, O(3) is bonded to one Na(1), one Na(2), two equivalent Na(3), and one Sn(1) atom to form distorted ONa4Sn square pyramids that share  a cornercorner with one O(4)Na4Sn2 octahedra, corners with three equivalent O(2)Na4Sn2 octahedra, corners with four equivalent O(1)Na5Sn octahedra, corners with two equivalent O(3)Na4Sn square pyramids,  an edgeedge with one O(4)Na4Sn2 octahedra, edges with two equivalent O(2)Na4Sn2 octahedra, and edges with two equivalent O(1)Na5Sn octahedra. The corner-sharing octahedral tilt angles range from 9-93°. In the fourth O site, O(4) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Sn(1) atoms to form ONa4Sn2 octahedra that share corners with six equivalent O(2)Na4Sn2 octahedra, corners with two equivalent O(3)Na4Sn square pyramids, edges with two equivalent O(2)Na4Sn2 octahedra, edges with four equivalent O(1)Na5Sn octahedra, and edges with two equivalent O(3)Na4Sn square pyramids. The corner-sharing octahedral tilt angles range from 1-21°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na6Sn2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.632
_cell_length_b   6.632
_cell_length_c   11.050
_cell_angle_alpha   79.245
_cell_angle_beta   79.245
_cell_angle_gamma   59.974
_symmetry_Int_Tables_number   1
_cell_volume   410.851
_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  0.530  0.326  0.122  1.0
  Na  Na1  1  0.076  0.785  0.097  1.0
  Na  Na2  1  0.326  0.530  0.622  1.0
  Na  Na3  1  0.785  0.076  0.597  1.0
  Na  Na4  1  0.672  0.925  0.381  1.0
  Na  Na5  1  0.925  0.672  0.881  1.0
  Na  Na6  1  0.075  0.328  0.119  1.0
  Na  Na7  1  0.328  0.075  0.619  1.0
  Na  Na8  1  0.215  0.924  0.403  1.0
  Na  Na9  1  0.674  0.470  0.378  1.0
  Na  Na10  1  0.924  0.215  0.903  1.0
  Na  Na11  1  0.470  0.674  0.878  1.0
  Sn  Sn12  1  0.176  0.470  0.374  1.0
  Sn  Sn13  1  0.470  0.176  0.874  1.0
  Sn  Sn14  1  0.530  0.824  0.126  1.0
  Sn  Sn15  1  0.824  0.530  0.626  1.0
  O  O16  1  0.469  0.277  0.459  1.0
  O  O17  1  0.277  0.469  0.959  1.0
  O  O18  1  0.719  0.996  0.003  1.0
  O  O19  1  0.921  0.606  0.258  1.0
  O  O20  1  0.394  0.079  0.242  1.0
  O  O21  1  0.996  0.719  0.503  1.0
  O  O22  1  0.004  0.281  0.497  1.0
  O  O23  1  0.606  0.921  0.758  1.0
  O  O24  1  0.079  0.394  0.742  1.0
  O  O25  1  0.281  0.004  0.997  1.0
  O  O26  1  0.723  0.531  0.041  1.0
  O  O27  1  0.344  0.656  0.250  1.0
  O  O28  1  0.531  0.723  0.541  1.0
  O  O29  1  0.656  0.344  0.750  1.0
[/CIF]
.