The compound described by Na6(NiO2)7 crystallizes in the trigonal R-3 space group. Na(1) is bonded to one O(3), two equivalent O(1), and three equivalent O(2) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with five equivalent Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with five equivalent Na(1)O6 octahedra, and edges with five equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-22°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), two equivalent O(2), and three equivalent O(1) atoms to form NiO6 octahedra that share corners with five equivalent Na(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with five equivalent Na(1)O6 octahedra, and edges with five equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-22°. In the second Ni site, Ni(2) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Na(1)O6 octahedra, edges with six equivalent Na(1)O6 octahedra, and edges with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1) and three equivalent Ni(1) atoms to form ONa2Ni3 square pyramids that share  a cornercorner with one O(3)Na3Ni3 octahedra, corners with two equivalent O(2)Na3Ni3 octahedra, corners with six equivalent O(1)Na2Ni3 square pyramids, edges with two equivalent O(3)Na3Ni3 octahedra, edges with five equivalent O(2)Na3Ni3 octahedra, and  an edgeedge with one O(1)Na2Ni3 square pyramid. The corner-sharing octahedral tilt angles range from 5-9°. In the second O site, O(2) is bonded to three equivalent Na(1), one Ni(2), and two equivalent Ni(1) atoms to form ONa3Ni3 octahedra that share  a cornercorner with one O(3)Na3Ni3 octahedra, corners with three equivalent O(2)Na3Ni3 octahedra, corners with two equivalent O(1)Na2Ni3 square pyramids, edges with two equivalent O(3)Na3Ni3 octahedra, edges with five equivalent O(2)Na3Ni3 octahedra, and edges with five equivalent O(1)Na2Ni3 square pyramids. The corner-sharing octahedral tilt angles range from 0-6°. In the third O site, O(3) is bonded to three equivalent Na(1) and three equivalent Ni(1) atoms to form ONa3Ni3 octahedra that share corners with three equivalent O(2)Na3Ni3 octahedra, corners with three equivalent O(1)Na2Ni3 square pyramids, edges with six equivalent O(2)Na3Ni3 octahedra, and edges with six equivalent O(1)Na2Ni3 square pyramids. The corner-sharing octahedral tilt angles are 2°. is represented by the CIF card [CIF]
data_Na6(NiO2)7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.864
_cell_length_b   6.864
_cell_length_c   6.864
_cell_angle_alpha   68.276
_cell_angle_beta   68.276
_cell_angle_gamma   68.276
_symmetry_Int_Tables_number   1
_cell_volume   268.745
_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  0.723  0.869  0.421  1.0
  Na  Na1  1  0.131  0.579  0.277  1.0
  Na  Na2  1  0.421  0.723  0.869  1.0
  Na  Na3  1  0.579  0.277  0.131  1.0
  Na  Na4  1  0.869  0.421  0.723  1.0
  Na  Na5  1  0.277  0.131  0.579  1.0
  Ni  Ni6  1  0.354  0.924  0.219  1.0
  Ni  Ni7  1  0.781  0.646  0.076  1.0
  Ni  Ni8  1  0.076  0.781  0.646  1.0
  Ni  Ni9  1  0.500  0.500  0.500  1.0
  Ni  Ni10  1  0.924  0.219  0.354  1.0
  Ni  Ni11  1  0.219  0.354  0.924  1.0
  Ni  Ni12  1  0.646  0.076  0.781  1.0
  O  O13  1  0.067  0.900  0.352  1.0
  O  O14  1  0.648  0.933  0.100  1.0
  O  O15  1  0.467  0.621  0.215  1.0
  O  O16  1  0.379  0.785  0.533  1.0
  O  O17  1  0.230  0.230  0.230  1.0
  O  O18  1  0.785  0.533  0.379  1.0
  O  O19  1  0.215  0.467  0.621  1.0
  O  O20  1  0.100  0.648  0.933  1.0
  O  O21  1  0.900  0.352  0.067  1.0
  O  O22  1  0.770  0.770  0.770  1.0
  O  O23  1  0.533  0.379  0.785  1.0
  O  O24  1  0.621  0.215  0.467  1.0
  O  O25  1  0.352  0.067  0.900  1.0
  O  O26  1  0.933  0.100  0.648  1.0
[/CIF]
.
The compound described by Na6(NiO2)7 crystallizes in the trigonal R-3 space group. Na(1) is bonded to one O(3), two equivalent O(1), and three equivalent O(2) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with five equivalent Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with five equivalent Na(1)O6 octahedra, and edges with five equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-22°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), two equivalent O(2), and three equivalent O(1) atoms to form NiO6 octahedra that share corners with five equivalent Na(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with five equivalent Na(1)O6 octahedra, and edges with five equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-22°. In the second Ni site, Ni(2) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Na(1)O6 octahedra, edges with six equivalent Na(1)O6 octahedra, and edges with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1) and three equivalent Ni(1) atoms to form ONa2Ni3 square pyramids that share  a cornercorner with one O(3)Na3Ni3 octahedra, corners with two equivalent O(2)Na3Ni3 octahedra, corners with six equivalent O(1)Na2Ni3 square pyramids, edges with two equivalent O(3)Na3Ni3 octahedra, edges with five equivalent O(2)Na3Ni3 octahedra, and  an edgeedge with one O(1)Na2Ni3 square pyramid. The corner-sharing octahedral tilt angles range from 5-9°. In the second O site, O(2) is bonded to three equivalent Na(1), one Ni(2), and two equivalent Ni(1) atoms to form ONa3Ni3 octahedra that share  a cornercorner with one O(3)Na3Ni3 octahedra, corners with three equivalent O(2)Na3Ni3 octahedra, corners with two equivalent O(1)Na2Ni3 square pyramids, edges with two equivalent O(3)Na3Ni3 octahedra, edges with five equivalent O(2)Na3Ni3 octahedra, and edges with five equivalent O(1)Na2Ni3 square pyramids. The corner-sharing octahedral tilt angles range from 0-6°. In the third O site, O(3) is bonded to three equivalent Na(1) and three equivalent Ni(1) atoms to form ONa3Ni3 octahedra that share corners with three equivalent O(2)Na3Ni3 octahedra, corners with three equivalent O(1)Na2Ni3 square pyramids, edges with six equivalent O(2)Na3Ni3 octahedra, and edges with six equivalent O(1)Na2Ni3 square pyramids. The corner-sharing octahedral tilt angles are 2°. is represented by the CIF card [CIF]
data_Na6(NiO2)7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.864
_cell_length_b   6.864
_cell_length_c   6.864
_cell_angle_alpha   68.276
_cell_angle_beta   68.276
_cell_angle_gamma   68.276
_symmetry_Int_Tables_number   1
_cell_volume   268.745
_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  0.723  0.869  0.421  1.0
  Na  Na1  1  0.131  0.579  0.277  1.0
  Na  Na2  1  0.421  0.723  0.869  1.0
  Na  Na3  1  0.579  0.277  0.131  1.0
  Na  Na4  1  0.869  0.421  0.723  1.0
  Na  Na5  1  0.277  0.131  0.579  1.0
  Ni  Ni6  1  0.354  0.924  0.219  1.0
  Ni  Ni7  1  0.781  0.646  0.076  1.0
  Ni  Ni8  1  0.076  0.781  0.646  1.0
  Ni  Ni9  1  0.500  0.500  0.500  1.0
  Ni  Ni10  1  0.924  0.219  0.354  1.0
  Ni  Ni11  1  0.219  0.354  0.924  1.0
  Ni  Ni12  1  0.646  0.076  0.781  1.0
  O  O13  1  0.067  0.900  0.352  1.0
  O  O14  1  0.648  0.933  0.100  1.0
  O  O15  1  0.467  0.621  0.215  1.0
  O  O16  1  0.379  0.785  0.533  1.0
  O  O17  1  0.230  0.230  0.230  1.0
  O  O18  1  0.785  0.533  0.379  1.0
  O  O19  1  0.215  0.467  0.621  1.0
  O  O20  1  0.100  0.648  0.933  1.0
  O  O21  1  0.900  0.352  0.067  1.0
  O  O22  1  0.770  0.770  0.770  1.0
  O  O23  1  0.533  0.379  0.785  1.0
  O  O24  1  0.621  0.215  0.467  1.0
  O  O25  1  0.352  0.067  0.900  1.0
  O  O26  1  0.933  0.100  0.648  1.0
[/CIF]
.