The material described by Na4Mg(NiO3)2 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(2)O5 square pyramid, corners with three equivalent Ni(2)O4 tetrahedra, and  an edgeedge with one Na(2)O5 square pyramid. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(6) atom to form distorted NaO5 square pyramids that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra, and  an edgeedge with one Ni(2)O4 tetrahedra. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(5), and one O(6) atom. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. In the second Ni site, Ni(2) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form NiO4 tetrahedra that share  a cornercorner with one Na(2)O5 square pyramid, corners with three equivalent Na(1)O4 tetrahedra, and  an edgeedge with one Na(2)O5 square pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mg(1), and one Ni(1) atom to form distorted ONa4MgNi octahedra that share corners with three equivalent O(3)Na2MgNi tetrahedra, corners with two equivalent O(2)Na3Ni2 trigonal bipyramids, corners with three equivalent O(5)Na3MgNi trigonal bipyramids,  an edgeedge with one O(5)Na3MgNi trigonal bipyramid, and  an edgeedge with one O(2)Na3Ni2 trigonal bipyramid. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(3), one Ni(1), and one Ni(2) atom to form distorted ONa3Ni2 trigonal bipyramids that share corners with two equivalent O(1)Na4MgNi octahedra, corners with two equivalent O(3)Na2MgNi tetrahedra,  a cornercorner with one O(5)Na3MgNi trigonal bipyramid,  an edgeedge with one O(1)Na4MgNi octahedra, and  an edgeedge with one O(5)Na3MgNi trigonal bipyramid. The corner-sharing octahedral tilt angles range from 8-71°. In the third O site, O(3) is bonded to one Na(2), one Na(4), one Mg(1), and one Ni(2) atom to form ONa2MgNi tetrahedra that share corners with three equivalent O(1)Na4MgNi octahedra, corners with two equivalent O(2)Na3Ni2 trigonal bipyramids, and corners with three equivalent O(5)Na3MgNi trigonal bipyramids. The corner-sharing octahedral tilt angles range from 57-69°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Mg(1), one Ni(1), and one Ni(2) atom. In the fifth O site, O(5) is bonded to one Na(2), one Na(3), one Na(4), one Mg(1), and one Ni(1) atom to form distorted ONa3MgNi trigonal bipyramids that share corners with three equivalent O(1)Na4MgNi octahedra, corners with three equivalent O(3)Na2MgNi tetrahedra,  a cornercorner with one O(2)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(1)Na4MgNi octahedra, and  an edgeedge with one O(2)Na3Ni2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 17-64°. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Ni(1), and one Ni(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Mg(NiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.647
_cell_length_b   6.058
_cell_length_c   6.573
_cell_angle_alpha   80.529
_cell_angle_beta   116.391
_cell_angle_gamma   67.463
_symmetry_Int_Tables_number   1
_cell_volume   170.111
_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  0.981  0.277  0.522  1.0
  Na  Na1  1  0.891  0.925  0.259  1.0
  Na  Na2  1  0.470  0.381  0.703  1.0
  Na  Na3  1  0.161  0.858  0.968  1.0
  Mg  Mg4  1  0.576  0.836  0.575  1.0
  Ni  Ni5  1  0.675  0.643  0.980  1.0
  Ni  Ni6  1  0.270  0.330  0.103  1.0
  O  O7  1  0.283  0.812  0.666  1.0
  O  O8  1  0.092  0.479  0.269  1.0
  O  O9  1  0.458  0.971  0.241  1.0
  O  O10  1  0.892  0.453  0.796  1.0
  O  O11  1  0.695  0.941  0.856  1.0
  O  O12  1  0.570  0.406  0.122  1.0
[/CIF]
.
The material described by Na4Mg(NiO3)2 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(2)O5 square pyramid, corners with three equivalent Ni(2)O4 tetrahedra, and  an edgeedge with one Na(2)O5 square pyramid. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(6) atom to form distorted NaO5 square pyramids that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra, and  an edgeedge with one Ni(2)O4 tetrahedra. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(5), and one O(6) atom. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. In the second Ni site, Ni(2) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form NiO4 tetrahedra that share  a cornercorner with one Na(2)O5 square pyramid, corners with three equivalent Na(1)O4 tetrahedra, and  an edgeedge with one Na(2)O5 square pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mg(1), and one Ni(1) atom to form distorted ONa4MgNi octahedra that share corners with three equivalent O(3)Na2MgNi tetrahedra, corners with two equivalent O(2)Na3Ni2 trigonal bipyramids, corners with three equivalent O(5)Na3MgNi trigonal bipyramids,  an edgeedge with one O(5)Na3MgNi trigonal bipyramid, and  an edgeedge with one O(2)Na3Ni2 trigonal bipyramid. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(3), one Ni(1), and one Ni(2) atom to form distorted ONa3Ni2 trigonal bipyramids that share corners with two equivalent O(1)Na4MgNi octahedra, corners with two equivalent O(3)Na2MgNi tetrahedra,  a cornercorner with one O(5)Na3MgNi trigonal bipyramid,  an edgeedge with one O(1)Na4MgNi octahedra, and  an edgeedge with one O(5)Na3MgNi trigonal bipyramid. The corner-sharing octahedral tilt angles range from 8-71°. In the third O site, O(3) is bonded to one Na(2), one Na(4), one Mg(1), and one Ni(2) atom to form ONa2MgNi tetrahedra that share corners with three equivalent O(1)Na4MgNi octahedra, corners with two equivalent O(2)Na3Ni2 trigonal bipyramids, and corners with three equivalent O(5)Na3MgNi trigonal bipyramids. The corner-sharing octahedral tilt angles range from 57-69°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Mg(1), one Ni(1), and one Ni(2) atom. In the fifth O site, O(5) is bonded to one Na(2), one Na(3), one Na(4), one Mg(1), and one Ni(1) atom to form distorted ONa3MgNi trigonal bipyramids that share corners with three equivalent O(1)Na4MgNi octahedra, corners with three equivalent O(3)Na2MgNi tetrahedra,  a cornercorner with one O(2)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(1)Na4MgNi octahedra, and  an edgeedge with one O(2)Na3Ni2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 17-64°. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Ni(1), and one Ni(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Mg(NiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.647
_cell_length_b   6.058
_cell_length_c   6.573
_cell_angle_alpha   80.529
_cell_angle_beta   116.391
_cell_angle_gamma   67.463
_symmetry_Int_Tables_number   1
_cell_volume   170.111
_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  0.981  0.277  0.522  1.0
  Na  Na1  1  0.891  0.925  0.259  1.0
  Na  Na2  1  0.470  0.381  0.703  1.0
  Na  Na3  1  0.161  0.858  0.968  1.0
  Mg  Mg4  1  0.576  0.836  0.575  1.0
  Ni  Ni5  1  0.675  0.643  0.980  1.0
  Ni  Ni6  1  0.270  0.330  0.103  1.0
  O  O7  1  0.283  0.812  0.666  1.0
  O  O8  1  0.092  0.479  0.269  1.0
  O  O9  1  0.458  0.971  0.241  1.0
  O  O10  1  0.892  0.453  0.796  1.0
  O  O11  1  0.695  0.941  0.856  1.0
  O  O12  1  0.570  0.406  0.122  1.0
[/CIF]
.