The material described by Na4Mg(FeO2)4 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(5), and one O(8) atom. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(6), and one O(7) atom. In the third Na site, Na(3) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form NaO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(8) atom. Mg(1) is bonded to one O(1), one O(4), one O(5), one O(7), and one O(8) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Fe(1)O4 tetrahedra,  an edgeedge with one Fe(3)O4 tetrahedra, and  an edgeedge with one Fe(4)O4 tetrahedra. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form distorted FeO4 tetrahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form FeO4 tetrahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(3)O4 tetrahedra. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(7), and one O(8) atom to form distorted FeO4 tetrahedra that share corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Mg(1)O5 square pyramids, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Mg(1), one Fe(1), and one Fe(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Fe(2), and one Fe(3) atom. In the third O site, O(3) is bonded to one Na(3), one Na(4), one Fe(2), and one Fe(3) atom to form distorted ONa2Fe2 tetrahedra that share corners with two equivalent O(6)Na2Fe2 tetrahedra, corners with two equivalent O(7)Na2MgFe2 trigonal bipyramids, and corners with two equivalent O(8)Na2MgFe2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Mg(1), one Fe(1), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Na(1), one Na(4), one Mg(1), one Fe(1), and one Fe(2) atom. In the sixth O site, O(6) is bonded to one Na(2), one Na(3), one Fe(1), and one Fe(2) atom to form ONa2Fe2 tetrahedra that share corners with two equivalent O(3)Na2Fe2 tetrahedra and corners with two equivalent O(7)Na2MgFe2 trigonal bipyramids. In the seventh O site, O(7) is bonded to one Na(2), one Na(3), one Mg(1), one Fe(3), and one Fe(4) atom to form distorted ONa2MgFe2 trigonal bipyramids that share corners with two equivalent O(3)Na2Fe2 tetrahedra, corners with two equivalent O(6)Na2Fe2 tetrahedra,  a cornercorner with one O(8)Na2MgFe2 trigonal bipyramid, and  an edgeedge with one O(8)Na2MgFe2 trigonal bipyramid. In the eighth O site, O(8) is bonded to one Na(1), one Na(4), one Mg(1), one Fe(3), and one Fe(4) atom to form distorted ONa2MgFe2 trigonal bipyramids that share corners with two equivalent O(3)Na2Fe2 tetrahedra,  a cornercorner with one O(7)Na2MgFe2 trigonal bipyramid, and  an edgeedge with one O(7)Na2MgFe2 trigonal bipyramid. is represented by the CIF file [CIF]
data_Na4Mg(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.398
_cell_length_b   5.889
_cell_length_c   7.349
_cell_angle_alpha   86.934
_cell_angle_beta   87.854
_cell_angle_gamma   85.368
_symmetry_Int_Tables_number   1
_cell_volume   232.398
_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  0.437  0.976  0.421  1.0
  Na  Na1  1  0.949  0.060  0.645  1.0
  Na  Na2  1  0.003  0.565  0.858  1.0
  Na  Na3  1  0.478  0.344  0.067  1.0
  Mg  Mg4  1  0.663  0.729  0.174  1.0
  Fe  Fe5  1  0.053  0.553  0.378  1.0
  Fe  Fe6  1  0.523  0.455  0.607  1.0
  Fe  Fe7  1  0.464  0.933  0.853  1.0
  Fe  Fe8  1  0.995  0.075  0.139  1.0
  O  O9  1  0.874  0.892  0.345  1.0
  O  O10  1  0.394  0.166  0.664  1.0
  O  O11  1  0.423  0.612  0.822  1.0
  O  O12  1  0.901  0.405  0.147  1.0
  O  O13  1  0.423  0.575  0.363  1.0
  O  O14  1  0.871  0.438  0.595  1.0
  O  O15  1  0.829  0.924  0.958  1.0
  O  O16  1  0.347  0.996  0.122  1.0
[/CIF]
.
The material described by Na4Mg(FeO2)4 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(5), and one O(8) atom. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(6), and one O(7) atom. In the third Na site, Na(3) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form NaO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(8) atom. Mg(1) is bonded to one O(1), one O(4), one O(5), one O(7), and one O(8) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Fe(1)O4 tetrahedra,  an edgeedge with one Fe(3)O4 tetrahedra, and  an edgeedge with one Fe(4)O4 tetrahedra. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form distorted FeO4 tetrahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form FeO4 tetrahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(3)O4 tetrahedra. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(7), and one O(8) atom to form distorted FeO4 tetrahedra that share corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Mg(1)O5 square pyramids, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Mg(1), one Fe(1), and one Fe(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Fe(2), and one Fe(3) atom. In the third O site, O(3) is bonded to one Na(3), one Na(4), one Fe(2), and one Fe(3) atom to form distorted ONa2Fe2 tetrahedra that share corners with two equivalent O(6)Na2Fe2 tetrahedra, corners with two equivalent O(7)Na2MgFe2 trigonal bipyramids, and corners with two equivalent O(8)Na2MgFe2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Mg(1), one Fe(1), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Na(1), one Na(4), one Mg(1), one Fe(1), and one Fe(2) atom. In the sixth O site, O(6) is bonded to one Na(2), one Na(3), one Fe(1), and one Fe(2) atom to form ONa2Fe2 tetrahedra that share corners with two equivalent O(3)Na2Fe2 tetrahedra and corners with two equivalent O(7)Na2MgFe2 trigonal bipyramids. In the seventh O site, O(7) is bonded to one Na(2), one Na(3), one Mg(1), one Fe(3), and one Fe(4) atom to form distorted ONa2MgFe2 trigonal bipyramids that share corners with two equivalent O(3)Na2Fe2 tetrahedra, corners with two equivalent O(6)Na2Fe2 tetrahedra,  a cornercorner with one O(8)Na2MgFe2 trigonal bipyramid, and  an edgeedge with one O(8)Na2MgFe2 trigonal bipyramid. In the eighth O site, O(8) is bonded to one Na(1), one Na(4), one Mg(1), one Fe(3), and one Fe(4) atom to form distorted ONa2MgFe2 trigonal bipyramids that share corners with two equivalent O(3)Na2Fe2 tetrahedra,  a cornercorner with one O(7)Na2MgFe2 trigonal bipyramid, and  an edgeedge with one O(7)Na2MgFe2 trigonal bipyramid. is represented by the CIF file [CIF]
data_Na4Mg(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.398
_cell_length_b   5.889
_cell_length_c   7.349
_cell_angle_alpha   86.934
_cell_angle_beta   87.854
_cell_angle_gamma   85.368
_symmetry_Int_Tables_number   1
_cell_volume   232.398
_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  0.437  0.976  0.421  1.0
  Na  Na1  1  0.949  0.060  0.645  1.0
  Na  Na2  1  0.003  0.565  0.858  1.0
  Na  Na3  1  0.478  0.344  0.067  1.0
  Mg  Mg4  1  0.663  0.729  0.174  1.0
  Fe  Fe5  1  0.053  0.553  0.378  1.0
  Fe  Fe6  1  0.523  0.455  0.607  1.0
  Fe  Fe7  1  0.464  0.933  0.853  1.0
  Fe  Fe8  1  0.995  0.075  0.139  1.0
  O  O9  1  0.874  0.892  0.345  1.0
  O  O10  1  0.394  0.166  0.664  1.0
  O  O11  1  0.423  0.612  0.822  1.0
  O  O12  1  0.901  0.405  0.147  1.0
  O  O13  1  0.423  0.575  0.363  1.0
  O  O14  1  0.871  0.438  0.595  1.0
  O  O15  1  0.829  0.924  0.958  1.0
  O  O16  1  0.347  0.996  0.122  1.0
[/CIF]
.