The compound described by Mg(FeO2)4 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(4), two equivalent O(6), and two equivalent O(7) atoms to form MgO5 square pyramids that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Mg(1)O5 square pyramids, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-55°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and edges with two equivalent Mg(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 48-53°. In the second Fe site, Fe(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and  a faceface with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 48-54°. In the third Fe site, Fe(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. In the fourth Fe site, Fe(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  an edgeedge with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 51-54°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(1) atoms to form OMgFe3 trigonal pyramids that share corners with two equivalent O(4)MgFe3 trigonal pyramids, edges with two equivalent O(7)Mg2Fe3 square pyramids, and edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Fe(3), and two equivalent Fe(2) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with two equivalent O(7)Mg2Fe3 square pyramids,  an edgeedge with one O(7)Mg2Fe3 square pyramid, edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(4)MgFe3 trigonal pyramids. In the seventh O site, O(7) is bonded to two equivalent Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form OMg2Fe3 square pyramids that share corners with two equivalent O(6)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(7)Mg2Fe3 square pyramids,  an edgeedge with one O(6)Mg2Fe3 trigonal bipyramid, and edges with two equivalent O(4)MgFe3 trigonal pyramids. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(3) atoms. is represented by the CIF card [CIF]
data_Mg(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.993
_cell_length_b   7.271
_cell_length_c   7.463
_cell_angle_alpha   80.852
_cell_angle_beta   78.419
_cell_angle_gamma   78.113
_symmetry_Int_Tables_number   1
_cell_volume   154.539
_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
  Mg  Mg0  1  0.344  0.128  0.196  1.0
  Fe  Fe1  1  0.637  0.175  0.563  1.0
  Fe  Fe2  1  0.151  0.510  0.201  1.0
  Fe  Fe3  1  0.846  0.485  0.836  1.0
  Fe  Fe4  1  0.360  0.802  0.490  1.0
  O  O5  1  0.862  0.672  0.617  1.0
  O  O6  1  0.461  0.330  0.760  1.0
  O  O7  1  0.540  0.649  0.283  1.0
  O  O8  1  0.146  0.305  0.415  1.0
  O  O9  1  0.174  0.012  0.652  1.0
  O  O10  1  0.795  0.322  0.100  1.0
  O  O11  1  0.844  0.981  0.343  1.0
  O  O12  1  0.219  0.620  0.954  1.0
[/CIF]
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The compound described by Mg(FeO2)4 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(4), two equivalent O(6), and two equivalent O(7) atoms to form MgO5 square pyramids that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Mg(1)O5 square pyramids, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-55°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and edges with two equivalent Mg(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 48-53°. In the second Fe site, Fe(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and  a faceface with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 48-54°. In the third Fe site, Fe(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. In the fourth Fe site, Fe(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  an edgeedge with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 51-54°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(1) atoms to form OMgFe3 trigonal pyramids that share corners with two equivalent O(4)MgFe3 trigonal pyramids, edges with two equivalent O(7)Mg2Fe3 square pyramids, and edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Fe(3), and two equivalent Fe(2) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with two equivalent O(7)Mg2Fe3 square pyramids,  an edgeedge with one O(7)Mg2Fe3 square pyramid, edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(4)MgFe3 trigonal pyramids. In the seventh O site, O(7) is bonded to two equivalent Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form OMg2Fe3 square pyramids that share corners with two equivalent O(6)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(7)Mg2Fe3 square pyramids,  an edgeedge with one O(6)Mg2Fe3 trigonal bipyramid, and edges with two equivalent O(4)MgFe3 trigonal pyramids. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(3) atoms. is represented by the CIF card [CIF]
data_Mg(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.993
_cell_length_b   7.271
_cell_length_c   7.463
_cell_angle_alpha   80.852
_cell_angle_beta   78.419
_cell_angle_gamma   78.113
_symmetry_Int_Tables_number   1
_cell_volume   154.539
_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
  Mg  Mg0  1  0.344  0.128  0.196  1.0
  Fe  Fe1  1  0.637  0.175  0.563  1.0
  Fe  Fe2  1  0.151  0.510  0.201  1.0
  Fe  Fe3  1  0.846  0.485  0.836  1.0
  Fe  Fe4  1  0.360  0.802  0.490  1.0
  O  O5  1  0.862  0.672  0.617  1.0
  O  O6  1  0.461  0.330  0.760  1.0
  O  O7  1  0.540  0.649  0.283  1.0
  O  O8  1  0.146  0.305  0.415  1.0
  O  O9  1  0.174  0.012  0.652  1.0
  O  O10  1  0.795  0.322  0.100  1.0
  O  O11  1  0.844  0.981  0.343  1.0
  O  O12  1  0.219  0.620  0.954  1.0
[/CIF]
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