The structure described by Na2Mg(NiO2)5 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form distorted NaO6 octahedra that share  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(5)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Na site, Na(2) is bonded to one O(1), one O(10), one O(3), one O(4), one O(5), and one O(7) atom to form NaO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(5)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-17°. Mg(1) is bonded to one O(1), one O(10), one O(4), one O(6), one O(7), and one O(8) atom to form distorted MgO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with two equivalent Ni(5)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-13°. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Mg(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NiO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-19°. In the third Ni site, Ni(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-13°. In the fourth Ni site, Ni(4) is bonded to one O(10), one O(3), one O(4), one O(7), one O(8), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-16°. In the fifth Ni site, Ni(5) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-17°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), one Mg(1), one Ni(1), one Ni(2), and one Ni(3) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(5)Na2Ni3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid,  a cornercorner with one O(6)NaMgNi3 square pyramid, corners with three equivalent O(7)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, and edges with two equivalent O(4)NaMgNi3 square pyramids. In the second O site, O(2) is bonded in a distorted see-saw-like geometry to one Na(1), one Ni(1), one Ni(2), and one Ni(3) atom. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Ni(2), one Ni(3), and one Ni(4) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(5)Na2Ni3 square pyramid,  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(7)NaMgNi3 square pyramid,  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with two equivalent O(4)NaMgNi3 square pyramids,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(7)NaMgNi3 square pyramid, and  an edgeedge with one O(8)NaMgNi3 square pyramid. In the fourth O site, O(4) is bonded to one Na(2), one Mg(1), one Ni(2), one Ni(3), and one Ni(4) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with two equivalent O(3)Na2Ni3 square pyramids, corners with two equivalent O(6)NaMgNi3 square pyramids, corners with three equivalent O(10)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, edges with two equivalent O(1)NaMgNi3 square pyramids, and edges with two equivalent O(7)NaMgNi3 square pyramids. In the fifth O site, O(5) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(2), and one Ni(5) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid, corners with two equivalent O(6)NaMgNi3 square pyramids, corners with two equivalent O(7)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid, and  an edgeedge with one O(8)NaMgNi3 square pyramid. In the sixth O site, O(6) is bonded to one Na(1), one Mg(1), one Ni(1), one Ni(2), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid,  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with two equivalent O(5)Na2Ni3 square pyramids, corners with two equivalent O(4)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(7)NaMgNi3 square pyramid, and  an edgeedge with one O(8)NaMgNi3 square pyramid. In the seventh O site, O(7) is bonded to one Na(2), one Mg(1), one Ni(3), one Ni(4), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid, corners with two equivalent O(5)Na2Ni3 square pyramids, corners with two equivalent O(8)NaMgNi3 square pyramids, corners with three equivalent O(1)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, edges with two equivalent O(10)NaMgNi3 square pyramids, and edges with two equivalent O(4)NaMgNi3 square pyramids. In the eighth O site, O(8) is bonded to one Na(1), one Mg(1), one Ni(3), one Ni(4), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid,  a cornercorner with one O(4)NaMgNi3 square pyramid,  a cornercorner with one O(6)NaMgNi3 square pyramid, corners with two equivalent O(7)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid, and  an edgeedge with one O(7)NaMgNi3 square pyramid. In the ninth O site, O(9) is bonded in a see-saw-like geometry to one Na(1), one Ni(1), one Ni(4), and one Ni(5) atom. In the tenth O site, O(10) is bonded to one Na(2), one Mg(1), one Ni(1), one Ni(4), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(5)Na2Ni3 square pyramid,  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(6)NaMgNi3 square pyramid,  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with three equivalent O(4)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, and edges with two equivalent O(7)NaMgNi3 square pyramids. is represented by the CIF card [CIF]
data_Na2Mg(NiO2)5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.734
_cell_length_b   4.937
_cell_length_c   6.206
_cell_angle_alpha   76.936
_cell_angle_beta   107.327
_cell_angle_gamma   84.068
_symmetry_Int_Tables_number   1
_cell_volume   188.593
_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  0.008  0.993  0.507  1.0
  Na  Na1  1  0.384  0.804  0.881  1.0
  Mg  Mg2  1  0.606  0.209  0.107  1.0
  Ni  Ni3  1  0.997  0.002  0.001  1.0
  Ni  Ni4  1  0.197  0.402  0.196  1.0
  Ni  Ni5  1  0.404  0.803  0.386  1.0
  Ni  Ni6  1  0.600  0.199  0.601  1.0
  Ni  Ni7  1  0.799  0.597  0.811  1.0
  O  O8  1  0.274  0.113  0.067  1.0
  O  O9  1  0.125  0.720  0.299  1.0
  O  O10  1  0.332  0.094  0.517  1.0
  O  O11  1  0.476  0.494  0.259  1.0
  O  O12  1  0.062  0.710  0.874  1.0
  O  O13  1  0.917  0.285  0.132  1.0
  O  O14  1  0.536  0.478  0.751  1.0
  O  O15  1  0.669  0.921  0.454  1.0
  O  O16  1  0.881  0.278  0.706  1.0
  O  O17  1  0.726  0.907  0.940  1.0
[/CIF]
.
The structure described by Na2Mg(NiO2)5 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form distorted NaO6 octahedra that share  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(5)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Na site, Na(2) is bonded to one O(1), one O(10), one O(3), one O(4), one O(5), and one O(7) atom to form NaO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(5)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-17°. Mg(1) is bonded to one O(1), one O(10), one O(4), one O(6), one O(7), and one O(8) atom to form distorted MgO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with two equivalent Ni(5)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-13°. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Mg(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NiO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-19°. In the third Ni site, Ni(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-13°. In the fourth Ni site, Ni(4) is bonded to one O(10), one O(3), one O(4), one O(7), one O(8), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-16°. In the fifth Ni site, Ni(5) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-17°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), one Mg(1), one Ni(1), one Ni(2), and one Ni(3) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(5)Na2Ni3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid,  a cornercorner with one O(6)NaMgNi3 square pyramid, corners with three equivalent O(7)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, and edges with two equivalent O(4)NaMgNi3 square pyramids. In the second O site, O(2) is bonded in a distorted see-saw-like geometry to one Na(1), one Ni(1), one Ni(2), and one Ni(3) atom. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Ni(2), one Ni(3), and one Ni(4) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(5)Na2Ni3 square pyramid,  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(7)NaMgNi3 square pyramid,  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with two equivalent O(4)NaMgNi3 square pyramids,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(7)NaMgNi3 square pyramid, and  an edgeedge with one O(8)NaMgNi3 square pyramid. In the fourth O site, O(4) is bonded to one Na(2), one Mg(1), one Ni(2), one Ni(3), and one Ni(4) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with two equivalent O(3)Na2Ni3 square pyramids, corners with two equivalent O(6)NaMgNi3 square pyramids, corners with three equivalent O(10)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, edges with two equivalent O(1)NaMgNi3 square pyramids, and edges with two equivalent O(7)NaMgNi3 square pyramids. In the fifth O site, O(5) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(2), and one Ni(5) atom to form ONa2Ni3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid, corners with two equivalent O(6)NaMgNi3 square pyramids, corners with two equivalent O(7)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid, and  an edgeedge with one O(8)NaMgNi3 square pyramid. In the sixth O site, O(6) is bonded to one Na(1), one Mg(1), one Ni(1), one Ni(2), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid,  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with two equivalent O(5)Na2Ni3 square pyramids, corners with two equivalent O(4)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(7)NaMgNi3 square pyramid, and  an edgeedge with one O(8)NaMgNi3 square pyramid. In the seventh O site, O(7) is bonded to one Na(2), one Mg(1), one Ni(3), one Ni(4), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid, corners with two equivalent O(5)Na2Ni3 square pyramids, corners with two equivalent O(8)NaMgNi3 square pyramids, corners with three equivalent O(1)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, edges with two equivalent O(10)NaMgNi3 square pyramids, and edges with two equivalent O(4)NaMgNi3 square pyramids. In the eighth O site, O(8) is bonded to one Na(1), one Mg(1), one Ni(3), one Ni(4), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(3)Na2Ni3 square pyramid,  a cornercorner with one O(10)NaMgNi3 square pyramid,  a cornercorner with one O(4)NaMgNi3 square pyramid,  a cornercorner with one O(6)NaMgNi3 square pyramid, corners with two equivalent O(7)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(10)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid, and  an edgeedge with one O(7)NaMgNi3 square pyramid. In the ninth O site, O(9) is bonded in a see-saw-like geometry to one Na(1), one Ni(1), one Ni(4), and one Ni(5) atom. In the tenth O site, O(10) is bonded to one Na(2), one Mg(1), one Ni(1), one Ni(4), and one Ni(5) atom to form ONaMgNi3 square pyramids that share  a cornercorner with one O(5)Na2Ni3 square pyramid,  a cornercorner with one O(1)NaMgNi3 square pyramid,  a cornercorner with one O(6)NaMgNi3 square pyramid,  a cornercorner with one O(8)NaMgNi3 square pyramid, corners with three equivalent O(4)NaMgNi3 square pyramids,  an edgeedge with one O(3)Na2Ni3 square pyramid,  an edgeedge with one O(5)Na2Ni3 square pyramid,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(6)NaMgNi3 square pyramid,  an edgeedge with one O(8)NaMgNi3 square pyramid, and edges with two equivalent O(7)NaMgNi3 square pyramids. is represented by the CIF card [CIF]
data_Na2Mg(NiO2)5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.734
_cell_length_b   4.937
_cell_length_c   6.206
_cell_angle_alpha   76.936
_cell_angle_beta   107.327
_cell_angle_gamma   84.068
_symmetry_Int_Tables_number   1
_cell_volume   188.593
_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  0.008  0.993  0.507  1.0
  Na  Na1  1  0.384  0.804  0.881  1.0
  Mg  Mg2  1  0.606  0.209  0.107  1.0
  Ni  Ni3  1  0.997  0.002  0.001  1.0
  Ni  Ni4  1  0.197  0.402  0.196  1.0
  Ni  Ni5  1  0.404  0.803  0.386  1.0
  Ni  Ni6  1  0.600  0.199  0.601  1.0
  Ni  Ni7  1  0.799  0.597  0.811  1.0
  O  O8  1  0.274  0.113  0.067  1.0
  O  O9  1  0.125  0.720  0.299  1.0
  O  O10  1  0.332  0.094  0.517  1.0
  O  O11  1  0.476  0.494  0.259  1.0
  O  O12  1  0.062  0.710  0.874  1.0
  O  O13  1  0.917  0.285  0.132  1.0
  O  O14  1  0.536  0.478  0.751  1.0
  O  O15  1  0.669  0.921  0.454  1.0
  O  O16  1  0.881  0.278  0.706  1.0
  O  O17  1  0.726  0.907  0.940  1.0
[/CIF]
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