The material structure described by Na21In5O15 crystallizes in the monoclinic Cm space group. There are twelve inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form a mixture of corner and edge-sharing NaO4 tetrahedra. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the third Na site, Na(3) is bonded to one O(2), one O(3), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the fourth Na site, Na(4) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the fifth Na site, Na(5) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(6), and one O(7) atom. In the sixth Na site, Na(6) is bonded to one O(5), one O(6), one O(8), and one O(9) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the seventh Na site, Na(7) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the eighth Na site, Na(8) is bonded in a 4-coordinate geometry to one O(1), one O(6), one O(7), and one O(9) atom. In the ninth Na site, Na(9) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the tenth Na site, Na(10) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the eleventh Na site, Na(11) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the twelfth Na site, Na(12) is bonded to one O(2), one O(9), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. There are four inequivalent In sites. In the first In site, In(1) is bonded in a trigonal non-coplanar geometry to one In(2), one O(3), and two equivalent O(1) atoms. In the second In site, In(2) is bonded to one In(1), one In(4), and two equivalent In(3) atoms to form InIn4 tetrahedra that share corners with two equivalent O(1)Na5In octahedra, corners with two equivalent O(7)Na5In octahedra,  a cornercorner with one O(3)Na6In pentagonal bipyramid, corners with two equivalent O(8)Na6In pentagonal bipyramids, corners with two equivalent O(4)Na5In pentagonal pyramids, and corners with two equivalent O(5)Na5In pentagonal pyramids. The corner-sharing octahedral tilt angles range from 73-76°. In the third In site, In(3) is bonded in a trigonal non-coplanar geometry to one In(2), one O(4), one O(7), and one O(8) atom. In the fourth In site, In(4) is bonded in a trigonal non-coplanar geometry to one In(2), one O(9), and two equivalent O(5) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Na(10), one Na(2), one Na(5), one Na(8), one Na(9), and one In(1) atom to form distorted ONa5In octahedra that share  a cornercorner with one O(1)Na5In octahedra,  a cornercorner with one O(2)Na7 pentagonal bipyramid,  a cornercorner with one O(4)Na5In pentagonal pyramid,  a cornercorner with one O(5)Na5In pentagonal pyramid,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(7)Na5In octahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid,  an edgeedge with one O(8)Na6In pentagonal bipyramid, and  an edgeedge with one O(4)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles are 56°. In the second O site, O(2) is bonded to one Na(1), one Na(12), one Na(3), two equivalent Na(2), and two equivalent Na(4) atoms to form distorted ONa7 pentagonal bipyramids that share corners with two equivalent O(1)Na5In octahedra, edges with two equivalent O(7)Na5In octahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid, edges with two equivalent O(8)Na6In pentagonal bipyramids, edges with two equivalent O(4)Na5In pentagonal pyramids, and edges with two equivalent O(5)Na5In pentagonal pyramids. The corner-sharing octahedral tilt angles are 63°. In the third O site, O(3) is bonded to one Na(1), one Na(3), two equivalent Na(5), two equivalent Na(7), and one In(1) atom to form distorted ONa6In pentagonal bipyramids that share corners with two equivalent O(8)Na6In pentagonal bipyramids,  a cornercorner with one In(2)In4 tetrahedra, edges with two equivalent O(1)Na5In octahedra, edges with two equivalent O(7)Na5In octahedra,  an edgeedge with one O(2)Na7 pentagonal bipyramid, and edges with two equivalent O(5)Na5In pentagonal pyramids. In the fourth O site, O(4) is bonded to one Na(10), one Na(11), one Na(2), one Na(4), one Na(9), and one In(3) atom to form distorted ONa5In pentagonal pyramids that share  a cornercorner with one O(1)Na5In octahedra,  a cornercorner with one O(7)Na5In octahedra,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(1)Na5In octahedra,  an edgeedge with one O(7)Na5In octahedra,  an edgeedge with one O(2)Na7 pentagonal bipyramid, edges with two equivalent O(8)Na6In pentagonal bipyramids, and  an edgeedge with one O(5)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles range from 30-51°. In the fifth O site, O(5) is bonded to one Na(1), one Na(11), one Na(2), one Na(6), one Na(7), and one In(4) atom to form distorted ONa5In pentagonal pyramids that share  a cornercorner with one O(1)Na5In octahedra,  a cornercorner with one O(7)Na5In octahedra,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid,  an edgeedge with one O(8)Na6In pentagonal bipyramid,  an edgeedge with one O(2)Na7 pentagonal bipyramid,  an edgeedge with one O(4)Na5In pentagonal pyramid, and  an edgeedge with one O(5)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles range from 37-58°. In the sixth O site, O(6) is bonded in a 7-coordinate geometry to one Na(10), one Na(11), one Na(5), one Na(6), one Na(7), one Na(8), and one Na(9) atom. In the seventh O site, O(7) is bonded to one Na(11), one Na(3), one Na(4), one Na(5), one Na(8), and one In(3) atom to form distorted ONa5In octahedra that share  a cornercorner with one O(7)Na5In octahedra,  a cornercorner with one O(4)Na5In pentagonal pyramid,  a cornercorner with one O(5)Na5In pentagonal pyramid,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(1)Na5In octahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid,  an edgeedge with one O(8)Na6In pentagonal bipyramid,  an edgeedge with one O(2)Na7 pentagonal bipyramid, and  an edgeedge with one O(4)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles are 47°. In the eighth O site, O(8) is bonded to one Na(10), one Na(12), one Na(4), one Na(6), one Na(7), one Na(9), and one In(3) atom to form distorted ONa6In pentagonal bipyramids that share  a cornercorner with one O(3)Na6In pentagonal bipyramid,  a cornercorner with one O(8)Na6In pentagonal bipyramid,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(1)Na5In octahedra,  an edgeedge with one O(7)Na5In octahedra,  an edgeedge with one O(2)Na7 pentagonal bipyramid,  an edgeedge with one O(5)Na5In pentagonal pyramid, and edges with two equivalent O(4)Na5In pentagonal pyramids. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Na(12), two equivalent Na(6), two equivalent Na(8), and one In(4) atom. is represented by the CIF file [CIF]
data_Na21In5O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.706
_cell_length_b   9.706
_cell_length_c   9.695
_cell_angle_alpha   70.117
_cell_angle_beta   70.117
_cell_angle_gamma   108.544
_symmetry_Int_Tables_number   1
_cell_volume   703.914
_cell_formula_units_Z   1
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  0.441  0.441  0.272  1.0
  Na  Na1  1  0.571  0.776  0.988  1.0
  Na  Na2  1  0.213  0.213  0.219  1.0
  Na  Na3  1  0.268  0.546  0.016  1.0
  Na  Na4  1  1.000  0.302  0.438  1.0
  Na  Na5  1  0.457  0.754  0.522  1.0
  Na  Na6  1  0.216  0.433  0.568  1.0
  Na  Na7  1  0.775  0.981  0.456  1.0
  Na  Na8  1  0.224  0.785  0.788  1.0
  Na  Na9  1  0.554  0.007  0.720  1.0
  Na  Na10  1  0.260  0.719  0.279  1.0
  Na  Na11  1  0.007  0.554  0.720  1.0
  Na  Na12  1  0.719  0.260  0.279  1.0
  Na  Na13  1  0.785  0.224  0.788  1.0
  Na  Na14  1  0.776  0.571  0.988  1.0
  Na  Na15  1  0.433  0.216  0.568  1.0
  Na  Na16  1  0.981  0.775  0.456  1.0
  Na  Na17  1  0.546  0.268  0.016  1.0
  Na  Na18  1  0.754  0.457  0.522  1.0
  Na  Na19  1  0.302  1.000  0.438  1.0
  Na  Na20  1  0.473  0.473  0.775  1.0
  In  In21  1  0.992  0.992  0.698  1.0
  In  In22  1  0.991  0.991  0.998  1.0
  In  In23  1  0.008  0.295  0.993  1.0
  In  In24  1  0.295  0.008  0.993  1.0
  In  In25  1  0.697  0.697  0.284  1.0
  O  O26  1  0.793  0.025  0.694  1.0
  O  O27  1  0.477  0.477  0.020  1.0
  O  O28  1  0.209  0.209  0.488  1.0
  O  O29  1  0.330  0.805  0.988  1.0
  O  O30  1  0.462  0.668  0.315  1.0
  O  O31  1  0.493  0.002  0.521  1.0
  O  O32  1  0.993  0.264  0.222  1.0
  O  O33  1  0.224  0.525  0.786  1.0
  O  O34  1  0.805  0.330  0.988  1.0
  O  O35  1  0.002  0.493  0.521  1.0
  O  O36  1  0.668  0.462  0.315  1.0
  O  O37  1  0.025  0.793  0.694  1.0
  O  O38  1  0.264  0.993  0.222  1.0
  O  O39  1  0.525  0.224  0.786  1.0
  O  O40  1  0.705  0.705  0.497  1.0
[/CIF]
.
The material structure described by Na21In5O15 crystallizes in the monoclinic Cm space group. There are twelve inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form a mixture of corner and edge-sharing NaO4 tetrahedra. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the third Na site, Na(3) is bonded to one O(2), one O(3), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the fourth Na site, Na(4) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the fifth Na site, Na(5) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(6), and one O(7) atom. In the sixth Na site, Na(6) is bonded to one O(5), one O(6), one O(8), and one O(9) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the seventh Na site, Na(7) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the eighth Na site, Na(8) is bonded in a 4-coordinate geometry to one O(1), one O(6), one O(7), and one O(9) atom. In the ninth Na site, Na(9) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the tenth Na site, Na(10) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the eleventh Na site, Na(11) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. In the twelfth Na site, Na(12) is bonded to one O(2), one O(9), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing NaO4 tetrahedra. There are four inequivalent In sites. In the first In site, In(1) is bonded in a trigonal non-coplanar geometry to one In(2), one O(3), and two equivalent O(1) atoms. In the second In site, In(2) is bonded to one In(1), one In(4), and two equivalent In(3) atoms to form InIn4 tetrahedra that share corners with two equivalent O(1)Na5In octahedra, corners with two equivalent O(7)Na5In octahedra,  a cornercorner with one O(3)Na6In pentagonal bipyramid, corners with two equivalent O(8)Na6In pentagonal bipyramids, corners with two equivalent O(4)Na5In pentagonal pyramids, and corners with two equivalent O(5)Na5In pentagonal pyramids. The corner-sharing octahedral tilt angles range from 73-76°. In the third In site, In(3) is bonded in a trigonal non-coplanar geometry to one In(2), one O(4), one O(7), and one O(8) atom. In the fourth In site, In(4) is bonded in a trigonal non-coplanar geometry to one In(2), one O(9), and two equivalent O(5) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Na(10), one Na(2), one Na(5), one Na(8), one Na(9), and one In(1) atom to form distorted ONa5In octahedra that share  a cornercorner with one O(1)Na5In octahedra,  a cornercorner with one O(2)Na7 pentagonal bipyramid,  a cornercorner with one O(4)Na5In pentagonal pyramid,  a cornercorner with one O(5)Na5In pentagonal pyramid,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(7)Na5In octahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid,  an edgeedge with one O(8)Na6In pentagonal bipyramid, and  an edgeedge with one O(4)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles are 56°. In the second O site, O(2) is bonded to one Na(1), one Na(12), one Na(3), two equivalent Na(2), and two equivalent Na(4) atoms to form distorted ONa7 pentagonal bipyramids that share corners with two equivalent O(1)Na5In octahedra, edges with two equivalent O(7)Na5In octahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid, edges with two equivalent O(8)Na6In pentagonal bipyramids, edges with two equivalent O(4)Na5In pentagonal pyramids, and edges with two equivalent O(5)Na5In pentagonal pyramids. The corner-sharing octahedral tilt angles are 63°. In the third O site, O(3) is bonded to one Na(1), one Na(3), two equivalent Na(5), two equivalent Na(7), and one In(1) atom to form distorted ONa6In pentagonal bipyramids that share corners with two equivalent O(8)Na6In pentagonal bipyramids,  a cornercorner with one In(2)In4 tetrahedra, edges with two equivalent O(1)Na5In octahedra, edges with two equivalent O(7)Na5In octahedra,  an edgeedge with one O(2)Na7 pentagonal bipyramid, and edges with two equivalent O(5)Na5In pentagonal pyramids. In the fourth O site, O(4) is bonded to one Na(10), one Na(11), one Na(2), one Na(4), one Na(9), and one In(3) atom to form distorted ONa5In pentagonal pyramids that share  a cornercorner with one O(1)Na5In octahedra,  a cornercorner with one O(7)Na5In octahedra,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(1)Na5In octahedra,  an edgeedge with one O(7)Na5In octahedra,  an edgeedge with one O(2)Na7 pentagonal bipyramid, edges with two equivalent O(8)Na6In pentagonal bipyramids, and  an edgeedge with one O(5)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles range from 30-51°. In the fifth O site, O(5) is bonded to one Na(1), one Na(11), one Na(2), one Na(6), one Na(7), and one In(4) atom to form distorted ONa5In pentagonal pyramids that share  a cornercorner with one O(1)Na5In octahedra,  a cornercorner with one O(7)Na5In octahedra,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid,  an edgeedge with one O(8)Na6In pentagonal bipyramid,  an edgeedge with one O(2)Na7 pentagonal bipyramid,  an edgeedge with one O(4)Na5In pentagonal pyramid, and  an edgeedge with one O(5)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles range from 37-58°. In the sixth O site, O(6) is bonded in a 7-coordinate geometry to one Na(10), one Na(11), one Na(5), one Na(6), one Na(7), one Na(8), and one Na(9) atom. In the seventh O site, O(7) is bonded to one Na(11), one Na(3), one Na(4), one Na(5), one Na(8), and one In(3) atom to form distorted ONa5In octahedra that share  a cornercorner with one O(7)Na5In octahedra,  a cornercorner with one O(4)Na5In pentagonal pyramid,  a cornercorner with one O(5)Na5In pentagonal pyramid,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(1)Na5In octahedra,  an edgeedge with one O(3)Na6In pentagonal bipyramid,  an edgeedge with one O(8)Na6In pentagonal bipyramid,  an edgeedge with one O(2)Na7 pentagonal bipyramid, and  an edgeedge with one O(4)Na5In pentagonal pyramid. The corner-sharing octahedral tilt angles are 47°. In the eighth O site, O(8) is bonded to one Na(10), one Na(12), one Na(4), one Na(6), one Na(7), one Na(9), and one In(3) atom to form distorted ONa6In pentagonal bipyramids that share  a cornercorner with one O(3)Na6In pentagonal bipyramid,  a cornercorner with one O(8)Na6In pentagonal bipyramid,  a cornercorner with one In(2)In4 tetrahedra,  an edgeedge with one O(1)Na5In octahedra,  an edgeedge with one O(7)Na5In octahedra,  an edgeedge with one O(2)Na7 pentagonal bipyramid,  an edgeedge with one O(5)Na5In pentagonal pyramid, and edges with two equivalent O(4)Na5In pentagonal pyramids. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Na(12), two equivalent Na(6), two equivalent Na(8), and one In(4) atom. is represented by the CIF file [CIF]
data_Na21In5O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.706
_cell_length_b   9.706
_cell_length_c   9.695
_cell_angle_alpha   70.117
_cell_angle_beta   70.117
_cell_angle_gamma   108.544
_symmetry_Int_Tables_number   1
_cell_volume   703.914
_cell_formula_units_Z   1
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  0.441  0.441  0.272  1.0
  Na  Na1  1  0.571  0.776  0.988  1.0
  Na  Na2  1  0.213  0.213  0.219  1.0
  Na  Na3  1  0.268  0.546  0.016  1.0
  Na  Na4  1  1.000  0.302  0.438  1.0
  Na  Na5  1  0.457  0.754  0.522  1.0
  Na  Na6  1  0.216  0.433  0.568  1.0
  Na  Na7  1  0.775  0.981  0.456  1.0
  Na  Na8  1  0.224  0.785  0.788  1.0
  Na  Na9  1  0.554  0.007  0.720  1.0
  Na  Na10  1  0.260  0.719  0.279  1.0
  Na  Na11  1  0.007  0.554  0.720  1.0
  Na  Na12  1  0.719  0.260  0.279  1.0
  Na  Na13  1  0.785  0.224  0.788  1.0
  Na  Na14  1  0.776  0.571  0.988  1.0
  Na  Na15  1  0.433  0.216  0.568  1.0
  Na  Na16  1  0.981  0.775  0.456  1.0
  Na  Na17  1  0.546  0.268  0.016  1.0
  Na  Na18  1  0.754  0.457  0.522  1.0
  Na  Na19  1  0.302  1.000  0.438  1.0
  Na  Na20  1  0.473  0.473  0.775  1.0
  In  In21  1  0.992  0.992  0.698  1.0
  In  In22  1  0.991  0.991  0.998  1.0
  In  In23  1  0.008  0.295  0.993  1.0
  In  In24  1  0.295  0.008  0.993  1.0
  In  In25  1  0.697  0.697  0.284  1.0
  O  O26  1  0.793  0.025  0.694  1.0
  O  O27  1  0.477  0.477  0.020  1.0
  O  O28  1  0.209  0.209  0.488  1.0
  O  O29  1  0.330  0.805  0.988  1.0
  O  O30  1  0.462  0.668  0.315  1.0
  O  O31  1  0.493  0.002  0.521  1.0
  O  O32  1  0.993  0.264  0.222  1.0
  O  O33  1  0.224  0.525  0.786  1.0
  O  O34  1  0.805  0.330  0.988  1.0
  O  O35  1  0.002  0.493  0.521  1.0
  O  O36  1  0.668  0.462  0.315  1.0
  O  O37  1  0.025  0.793  0.694  1.0
  O  O38  1  0.264  0.993  0.222  1.0
  O  O39  1  0.525  0.224  0.786  1.0
  O  O40  1  0.705  0.705  0.497  1.0
[/CIF]
.