The compound described by Na4Mg(NiO3)2 crystallizes in the monoclinic Cm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(4), and two equivalent O(3) atoms. In the third Na site, Na(3) is bonded in a 1-coordinate geometry to one O(1), one O(4), two equivalent O(2), and four equivalent O(3) atoms. Mg(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form MgO4 tetrahedra that share corners with six equivalent Ni(1)O5 trigonal bipyramids. Ni(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NiO5 trigonal bipyramids that share corners with three equivalent Mg(1)O4 tetrahedra,  a cornercorner with one Ni(1)O5 trigonal bipyramid, and edges with two equivalent Ni(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal bipyramidal geometry to one Na(2), one Na(3), two equivalent Na(1), and one Mg(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(3), two equivalent Na(1), one Mg(1), and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 7-coordinate geometry to one Na(2), two equivalent Na(1), two equivalent Na(3), and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Mg(1), and two equivalent Ni(1) atoms. is represented by the CIF file [CIF]
data_Na4Mg(NiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.389
_cell_length_b   5.389
_cell_length_c   6.740
_cell_angle_alpha   80.999
_cell_angle_beta   99.001
_cell_angle_gamma   57.567
_symmetry_Int_Tables_number   1
_cell_volume   156.272
_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  0.039  0.353  0.521  1.0
  Na  Na1  1  0.647  0.961  0.521  1.0
  Na  Na2  1  0.550  0.450  0.727  1.0
  Na  Na3  1  0.084  0.916  0.889  1.0
  Mg  Mg4  1  0.133  0.867  0.290  1.0
  Ni  Ni5  1  0.752  0.623  0.049  1.0
  Ni  Ni6  1  0.377  0.248  0.049  1.0
  O  O7  1  0.113  0.887  0.568  1.0
  O  O8  1  0.172  0.492  0.227  1.0
  O  O9  1  0.508  0.828  0.227  1.0
  O  O10  1  0.972  0.449  0.857  1.0
  O  O11  1  0.551  0.028  0.857  1.0
  O  O12  1  0.740  0.260  0.111  1.0
[/CIF]
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The compound described by Na4Mg(NiO3)2 crystallizes in the monoclinic Cm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(4), and two equivalent O(3) atoms. In the third Na site, Na(3) is bonded in a 1-coordinate geometry to one O(1), one O(4), two equivalent O(2), and four equivalent O(3) atoms. Mg(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form MgO4 tetrahedra that share corners with six equivalent Ni(1)O5 trigonal bipyramids. Ni(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NiO5 trigonal bipyramids that share corners with three equivalent Mg(1)O4 tetrahedra,  a cornercorner with one Ni(1)O5 trigonal bipyramid, and edges with two equivalent Ni(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal bipyramidal geometry to one Na(2), one Na(3), two equivalent Na(1), and one Mg(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(3), two equivalent Na(1), one Mg(1), and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 7-coordinate geometry to one Na(2), two equivalent Na(1), two equivalent Na(3), and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Mg(1), and two equivalent Ni(1) atoms. is represented by the CIF file [CIF]
data_Na4Mg(NiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.389
_cell_length_b   5.389
_cell_length_c   6.740
_cell_angle_alpha   80.999
_cell_angle_beta   99.001
_cell_angle_gamma   57.567
_symmetry_Int_Tables_number   1
_cell_volume   156.272
_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  0.039  0.353  0.521  1.0
  Na  Na1  1  0.647  0.961  0.521  1.0
  Na  Na2  1  0.550  0.450  0.727  1.0
  Na  Na3  1  0.084  0.916  0.889  1.0
  Mg  Mg4  1  0.133  0.867  0.290  1.0
  Ni  Ni5  1  0.752  0.623  0.049  1.0
  Ni  Ni6  1  0.377  0.248  0.049  1.0
  O  O7  1  0.113  0.887  0.568  1.0
  O  O8  1  0.172  0.492  0.227  1.0
  O  O9  1  0.508  0.828  0.227  1.0
  O  O10  1  0.972  0.449  0.857  1.0
  O  O11  1  0.551  0.028  0.857  1.0
  O  O12  1  0.740  0.260  0.111  1.0
[/CIF]
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