The crystal structure described by Na12(CuO2)7 crystallizes in the monoclinic Cm space group. There are seven inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(6), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and one O(8) atom. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(5), and two equivalent O(8) atoms. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(6), one O(7), and one O(8) atom. In the fifth Na site, Na(5) is bonded in a 3-coordinate geometry to one O(1), one O(3), one O(5), and one O(6) atom. In the sixth Na site, Na(6) is bonded in a 4-coordinate geometry to one O(5), one O(6), one O(7), and one O(8) atom. In the seventh Na site, Na(7) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(7), and two equivalent O(5) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to one O(1), one O(2), one O(3), and one O(6) atom. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(6), and one O(7) atom. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(5), and one O(8) atom. In the fourth Cu site, Cu(4) is bonded in a rectangular see-saw-like geometry to two equivalent O(5) and two equivalent O(8) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(5), one Cu(1), and one Cu(3) atom to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-51°. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Cu(1), and one Cu(3) atom. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(4), one Na(5), one Cu(1), and one Cu(2) atom to form distorted ONa4Cu2 octahedra that share corners with two equivalent O(1)Na3Cu2 trigonal bipyramids,  an edgeedge with one O(4)Na4Cu2 octahedra,  an edgeedge with one O(8)Na4Cu2 octahedra, and  an edgeedge with one O(1)Na3Cu2 trigonal bipyramid. In the fourth O site, O(4) is bonded to one Na(3), one Na(7), two equivalent Na(4), and two equivalent Cu(2) atoms to form edge-sharing ONa4Cu2 octahedra. In the fifth O site, O(5) is bonded in a 7-coordinate geometry to one Na(2), one Na(3), one Na(5), one Na(6), one Na(7), one Cu(3), and one Cu(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(1), one Na(4), one Na(5), one Na(6), one Cu(1), and one Cu(2) atom. In the seventh O site, O(7) is bonded in a 7-coordinate geometry to one Na(7), two equivalent Na(4), two equivalent Na(6), and two equivalent Cu(2) atoms. In the eighth O site, O(8) is bonded to one Na(2), one Na(3), one Na(4), one Na(6), one Cu(3), and one Cu(4) atom to form ONa4Cu2 octahedra that share corners with two equivalent O(1)Na3Cu2 trigonal bipyramids,  an edgeedge with one O(3)Na4Cu2 octahedra,  an edgeedge with one O(4)Na4Cu2 octahedra, and  an edgeedge with one O(8)Na4Cu2 octahedra. is represented by the CIF card [CIF]
data_Na12(CuO2)7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.642
_cell_length_b   10.642
_cell_length_c   5.635
_cell_angle_alpha   81.898
_cell_angle_beta   81.893
_cell_angle_gamma   134.702
_symmetry_Int_Tables_number   1
_cell_volume   422.142
_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  0.162  0.618  0.383  1.0
  Na  Na1  1  0.618  0.162  0.383  1.0
  Na  Na2  1  0.767  0.465  0.612  1.0
  Na  Na3  1  0.465  0.767  0.612  1.0
  Na  Na4  1  0.624  0.624  0.619  1.0
  Na  Na5  1  0.304  0.454  0.389  1.0
  Na  Na6  1  0.454  0.304  0.389  1.0
  Na  Na7  1  0.249  0.888  0.641  1.0
  Na  Na8  1  0.888  0.249  0.641  1.0
  Na  Na9  1  0.027  0.860  0.335  1.0
  Na  Na10  1  0.860  0.027  0.335  1.0
  Na  Na11  1  0.056  0.056  0.671  1.0
  Cu  Cu12  1  0.460  0.033  0.996  1.0
  Cu  Cu13  1  0.033  0.460  0.996  1.0
  Cu  Cu14  1  0.335  0.193  0.972  1.0
  Cu  Cu15  1  0.193  0.335  0.972  1.0
  Cu  Cu16  1  0.881  0.595  0.024  1.0
  Cu  Cu17  1  0.595  0.881  0.024  1.0
  Cu  Cu18  1  0.739  0.739  0.034  1.0
  O  O19  1  0.570  1.000  0.771  1.0
  O  O20  1  1.000  0.569  0.771  1.0
  O  O21  1  0.465  0.907  0.252  1.0
  O  O22  1  0.907  0.465  0.252  1.0
  O  O23  1  0.458  0.162  0.739  1.0
  O  O24  1  0.162  0.458  0.739  1.0
  O  O25  1  0.321  0.321  0.724  1.0
  O  O26  1  0.880  0.736  0.774  1.0
  O  O27  1  0.736  0.880  0.774  1.0
  O  O28  1  0.352  0.067  0.227  1.0
  O  O29  1  0.067  0.352  0.227  1.0
  O  O30  1  0.186  0.186  0.230  1.0
  O  O31  1  0.756  0.609  0.277  1.0
  O  O32  1  0.609  0.756  0.277  1.0
[/CIF]
.
The crystal structure described by Na12(CuO2)7 crystallizes in the monoclinic Cm space group. There are seven inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(6), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and one O(8) atom. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(5), and two equivalent O(8) atoms. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(6), one O(7), and one O(8) atom. In the fifth Na site, Na(5) is bonded in a 3-coordinate geometry to one O(1), one O(3), one O(5), and one O(6) atom. In the sixth Na site, Na(6) is bonded in a 4-coordinate geometry to one O(5), one O(6), one O(7), and one O(8) atom. In the seventh Na site, Na(7) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(7), and two equivalent O(5) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to one O(1), one O(2), one O(3), and one O(6) atom. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(6), and one O(7) atom. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(5), and one O(8) atom. In the fourth Cu site, Cu(4) is bonded in a rectangular see-saw-like geometry to two equivalent O(5) and two equivalent O(8) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(5), one Cu(1), and one Cu(3) atom to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-51°. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Cu(1), and one Cu(3) atom. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(4), one Na(5), one Cu(1), and one Cu(2) atom to form distorted ONa4Cu2 octahedra that share corners with two equivalent O(1)Na3Cu2 trigonal bipyramids,  an edgeedge with one O(4)Na4Cu2 octahedra,  an edgeedge with one O(8)Na4Cu2 octahedra, and  an edgeedge with one O(1)Na3Cu2 trigonal bipyramid. In the fourth O site, O(4) is bonded to one Na(3), one Na(7), two equivalent Na(4), and two equivalent Cu(2) atoms to form edge-sharing ONa4Cu2 octahedra. In the fifth O site, O(5) is bonded in a 7-coordinate geometry to one Na(2), one Na(3), one Na(5), one Na(6), one Na(7), one Cu(3), and one Cu(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(1), one Na(4), one Na(5), one Na(6), one Cu(1), and one Cu(2) atom. In the seventh O site, O(7) is bonded in a 7-coordinate geometry to one Na(7), two equivalent Na(4), two equivalent Na(6), and two equivalent Cu(2) atoms. In the eighth O site, O(8) is bonded to one Na(2), one Na(3), one Na(4), one Na(6), one Cu(3), and one Cu(4) atom to form ONa4Cu2 octahedra that share corners with two equivalent O(1)Na3Cu2 trigonal bipyramids,  an edgeedge with one O(3)Na4Cu2 octahedra,  an edgeedge with one O(4)Na4Cu2 octahedra, and  an edgeedge with one O(8)Na4Cu2 octahedra. is represented by the CIF card [CIF]
data_Na12(CuO2)7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.642
_cell_length_b   10.642
_cell_length_c   5.635
_cell_angle_alpha   81.898
_cell_angle_beta   81.893
_cell_angle_gamma   134.702
_symmetry_Int_Tables_number   1
_cell_volume   422.142
_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  0.162  0.618  0.383  1.0
  Na  Na1  1  0.618  0.162  0.383  1.0
  Na  Na2  1  0.767  0.465  0.612  1.0
  Na  Na3  1  0.465  0.767  0.612  1.0
  Na  Na4  1  0.624  0.624  0.619  1.0
  Na  Na5  1  0.304  0.454  0.389  1.0
  Na  Na6  1  0.454  0.304  0.389  1.0
  Na  Na7  1  0.249  0.888  0.641  1.0
  Na  Na8  1  0.888  0.249  0.641  1.0
  Na  Na9  1  0.027  0.860  0.335  1.0
  Na  Na10  1  0.860  0.027  0.335  1.0
  Na  Na11  1  0.056  0.056  0.671  1.0
  Cu  Cu12  1  0.460  0.033  0.996  1.0
  Cu  Cu13  1  0.033  0.460  0.996  1.0
  Cu  Cu14  1  0.335  0.193  0.972  1.0
  Cu  Cu15  1  0.193  0.335  0.972  1.0
  Cu  Cu16  1  0.881  0.595  0.024  1.0
  Cu  Cu17  1  0.595  0.881  0.024  1.0
  Cu  Cu18  1  0.739  0.739  0.034  1.0
  O  O19  1  0.570  1.000  0.771  1.0
  O  O20  1  1.000  0.569  0.771  1.0
  O  O21  1  0.465  0.907  0.252  1.0
  O  O22  1  0.907  0.465  0.252  1.0
  O  O23  1  0.458  0.162  0.739  1.0
  O  O24  1  0.162  0.458  0.739  1.0
  O  O25  1  0.321  0.321  0.724  1.0
  O  O26  1  0.880  0.736  0.774  1.0
  O  O27  1  0.736  0.880  0.774  1.0
  O  O28  1  0.352  0.067  0.227  1.0
  O  O29  1  0.067  0.352  0.227  1.0
  O  O30  1  0.186  0.186  0.230  1.0
  O  O31  1  0.756  0.609  0.277  1.0
  O  O32  1  0.609  0.756  0.277  1.0
[/CIF]
.