The structure described by Na5(NiO2)9 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and two equivalent O(6) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(8), one O(9), and two equivalent O(7) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), one O(4), one O(5), one O(7), one O(8), and one O(9) atom to form edge-sharing NiO6 octahedra. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(6) atoms to form edge-sharing NiO6 octahedra. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms to form edge-sharing NiO6 octahedra. In the fourth Ni site, Ni(4) is bonded to one O(1), one O(2), one O(3), one O(9), and two equivalent O(8) atoms to form edge-sharing NiO6 octahedra. In the fifth Ni site, Ni(5) is bonded to two equivalent O(1), two equivalent O(7), and two equivalent O(9) atoms to form edge-sharing NiO6 octahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(3), one Ni(2), one Ni(4), and one Ni(5) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(1)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with two equivalent O(4)Na2Ni3 square pyramids, corners with two equivalent O(6)Na2Ni3 square pyramids,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid, edges with two equivalent O(2)Na2Ni3 square pyramids, edges with two equivalent O(7)Na2Ni3 square pyramids,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the second O site, O(2) is bonded to one Na(1), one Na(3), one Ni(2), one Ni(3), and one Ni(4) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with three equivalent O(8)NaNi3 trigonal pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(4)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid, edges with two equivalent O(1)Na2Ni3 square pyramids, edges with two equivalent O(6)Na2Ni3 square pyramids, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(3), and one Ni(4) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(1)Na2Ni3 square pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid, edges with two equivalent O(4)Na2Ni3 square pyramids, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(2), and one Ni(3) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(6)Na2Ni3 square pyramid, corners with two equivalent O(1)Na2Ni3 square pyramids,  a cornercorner with one O(8)NaNi3 trigonal pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid, edges with two equivalent O(3)Na2Ni3 square pyramids, and edges with two equivalent O(6)Na2Ni3 square pyramids. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to one Na(2), one Ni(1), and two equivalent Ni(3) atoms. In the sixth O site, O(6) is bonded to two equivalent Na(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni3 square pyramids. In the seventh O site, O(7) is bonded to two equivalent Na(3), one Ni(1), one Ni(2), and one Ni(5) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(1)Na2Ni3 square pyramid,  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with two equivalent O(6)Na2Ni3 square pyramids,  a cornercorner with one O(8)NaNi3 trigonal pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(4)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid, edges with two equivalent O(1)Na2Ni3 square pyramids,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and edges with two equivalent O(9)NaNi3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Na(3), one Ni(1), and two equivalent Ni(4) atoms to form ONaNi3 trigonal pyramids that share  a cornercorner with one O(1)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with three equivalent O(2)Na2Ni3 square pyramids, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(1)Na2Ni3 square pyramid,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the ninth O site, O(9) is bonded to one Na(3), one Ni(1), one Ni(4), and one Ni(5) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with two equivalent O(1)Na2Ni3 square pyramids, corners with two equivalent O(3)Na2Ni3 square pyramids,  a cornercorner with one O(9)NaNi3 trigonal pyramid, corners with two equivalent O(8)NaNi3 trigonal pyramids,  an edgeedge with one O(1)Na2Ni3 square pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid, edges with two equivalent O(7)Na2Ni3 square pyramids, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na5(NiO2)9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.716
_cell_length_b   7.449
_cell_length_c   8.569
_cell_angle_alpha   100.674
_cell_angle_beta   105.592
_cell_angle_gamma   95.330
_symmetry_Int_Tables_number   1
_cell_volume   341.398
_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  0.006  0.341  0.870  1.0
  Na  Na1  1  0.000  0.000  0.000  1.0
  Na  Na2  1  0.994  0.659  0.130  1.0
  Na  Na3  1  0.004  0.707  0.487  1.0
  Na  Na4  1  0.996  0.293  0.513  1.0
  Ni  Ni5  1  0.501  0.832  0.726  1.0
  Ni  Ni6  1  0.507  0.499  0.834  1.0
  Ni  Ni7  1  0.503  0.167  0.941  1.0
  Ni  Ni8  1  0.497  0.833  0.059  1.0
  Ni  Ni9  1  0.493  0.501  0.166  1.0
  Ni  Ni10  1  0.499  0.168  0.274  1.0
  Ni  Ni11  1  0.494  0.834  0.392  1.0
  Ni  Ni12  1  0.500  0.500  0.500  1.0
  Ni  Ni13  1  0.506  0.166  0.608  1.0
  O  O14  1  0.697  0.400  0.666  1.0
  O  O15  1  0.328  0.257  0.755  1.0
  O  O16  1  0.683  0.082  0.795  1.0
  O  O17  1  0.686  0.740  0.926  1.0
  O  O18  1  0.323  0.927  0.881  1.0
  O  O19  1  0.690  0.403  0.005  1.0
  O  O20  1  0.310  0.597  0.995  1.0
  O  O21  1  0.677  0.073  0.119  1.0
  O  O22  1  0.672  0.743  0.245  1.0
  O  O23  1  0.314  0.260  0.074  1.0
  O  O24  1  0.317  0.918  0.205  1.0
  O  O25  1  0.675  0.421  0.350  1.0
  O  O26  1  0.303  0.600  0.334  1.0
  O  O27  1  0.682  0.066  0.469  1.0
  O  O28  1  0.330  0.260  0.433  1.0
  O  O29  1  0.670  0.740  0.567  1.0
  O  O30  1  0.318  0.934  0.531  1.0
  O  O31  1  0.325  0.579  0.650  1.0
[/CIF]
.
The structure described by Na5(NiO2)9 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and two equivalent O(6) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(8), one O(9), and two equivalent O(7) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), one O(4), one O(5), one O(7), one O(8), and one O(9) atom to form edge-sharing NiO6 octahedra. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(6) atoms to form edge-sharing NiO6 octahedra. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms to form edge-sharing NiO6 octahedra. In the fourth Ni site, Ni(4) is bonded to one O(1), one O(2), one O(3), one O(9), and two equivalent O(8) atoms to form edge-sharing NiO6 octahedra. In the fifth Ni site, Ni(5) is bonded to two equivalent O(1), two equivalent O(7), and two equivalent O(9) atoms to form edge-sharing NiO6 octahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(3), one Ni(2), one Ni(4), and one Ni(5) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(1)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with two equivalent O(4)Na2Ni3 square pyramids, corners with two equivalent O(6)Na2Ni3 square pyramids,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid, edges with two equivalent O(2)Na2Ni3 square pyramids, edges with two equivalent O(7)Na2Ni3 square pyramids,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the second O site, O(2) is bonded to one Na(1), one Na(3), one Ni(2), one Ni(3), and one Ni(4) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with three equivalent O(8)NaNi3 trigonal pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(4)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid, edges with two equivalent O(1)Na2Ni3 square pyramids, edges with two equivalent O(6)Na2Ni3 square pyramids, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(3), and one Ni(4) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(1)Na2Ni3 square pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid, edges with two equivalent O(4)Na2Ni3 square pyramids, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(2), and one Ni(3) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(6)Na2Ni3 square pyramid, corners with two equivalent O(1)Na2Ni3 square pyramids,  a cornercorner with one O(8)NaNi3 trigonal pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid, edges with two equivalent O(3)Na2Ni3 square pyramids, and edges with two equivalent O(6)Na2Ni3 square pyramids. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to one Na(2), one Ni(1), and two equivalent Ni(3) atoms. In the sixth O site, O(6) is bonded to two equivalent Na(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni3 square pyramids. In the seventh O site, O(7) is bonded to two equivalent Na(3), one Ni(1), one Ni(2), and one Ni(5) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(1)Na2Ni3 square pyramid,  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with two equivalent O(6)Na2Ni3 square pyramids,  a cornercorner with one O(8)NaNi3 trigonal pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(4)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid, edges with two equivalent O(1)Na2Ni3 square pyramids,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and edges with two equivalent O(9)NaNi3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Na(3), one Ni(1), and two equivalent Ni(4) atoms to form ONaNi3 trigonal pyramids that share  a cornercorner with one O(1)Na2Ni3 square pyramid,  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with three equivalent O(2)Na2Ni3 square pyramids, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(1)Na2Ni3 square pyramid,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(7)Na2Ni3 square pyramid,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the ninth O site, O(9) is bonded to one Na(3), one Ni(1), one Ni(4), and one Ni(5) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(4)Na2Ni3 square pyramid,  a cornercorner with one O(7)Na2Ni3 square pyramid, corners with two equivalent O(1)Na2Ni3 square pyramids, corners with two equivalent O(3)Na2Ni3 square pyramids,  a cornercorner with one O(9)NaNi3 trigonal pyramid, corners with two equivalent O(8)NaNi3 trigonal pyramids,  an edgeedge with one O(1)Na2Ni3 square pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid, edges with two equivalent O(7)Na2Ni3 square pyramids, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na5(NiO2)9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.716
_cell_length_b   7.449
_cell_length_c   8.569
_cell_angle_alpha   100.674
_cell_angle_beta   105.592
_cell_angle_gamma   95.330
_symmetry_Int_Tables_number   1
_cell_volume   341.398
_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  0.006  0.341  0.870  1.0
  Na  Na1  1  0.000  0.000  0.000  1.0
  Na  Na2  1  0.994  0.659  0.130  1.0
  Na  Na3  1  0.004  0.707  0.487  1.0
  Na  Na4  1  0.996  0.293  0.513  1.0
  Ni  Ni5  1  0.501  0.832  0.726  1.0
  Ni  Ni6  1  0.507  0.499  0.834  1.0
  Ni  Ni7  1  0.503  0.167  0.941  1.0
  Ni  Ni8  1  0.497  0.833  0.059  1.0
  Ni  Ni9  1  0.493  0.501  0.166  1.0
  Ni  Ni10  1  0.499  0.168  0.274  1.0
  Ni  Ni11  1  0.494  0.834  0.392  1.0
  Ni  Ni12  1  0.500  0.500  0.500  1.0
  Ni  Ni13  1  0.506  0.166  0.608  1.0
  O  O14  1  0.697  0.400  0.666  1.0
  O  O15  1  0.328  0.257  0.755  1.0
  O  O16  1  0.683  0.082  0.795  1.0
  O  O17  1  0.686  0.740  0.926  1.0
  O  O18  1  0.323  0.927  0.881  1.0
  O  O19  1  0.690  0.403  0.005  1.0
  O  O20  1  0.310  0.597  0.995  1.0
  O  O21  1  0.677  0.073  0.119  1.0
  O  O22  1  0.672  0.743  0.245  1.0
  O  O23  1  0.314  0.260  0.074  1.0
  O  O24  1  0.317  0.918  0.205  1.0
  O  O25  1  0.675  0.421  0.350  1.0
  O  O26  1  0.303  0.600  0.334  1.0
  O  O27  1  0.682  0.066  0.469  1.0
  O  O28  1  0.330  0.260  0.433  1.0
  O  O29  1  0.670  0.740  0.567  1.0
  O  O30  1  0.318  0.934  0.531  1.0
  O  O31  1  0.325  0.579  0.650  1.0
[/CIF]
.