The structure described by MgFe2O4 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form MgO5 trigonal bipyramids that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-61°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted FeO5 trigonal bipyramids that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°. In the second Fe site, Fe(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with four equivalent Mg(1)O5 trigonal bipyramids, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with four equivalent Fe(2)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(1) atoms to form OMgFe3 tetrahedra that share corners with two equivalent O(1)MgFe3 tetrahedra,  a cornercorner with one O(4)Mg2Fe3 trigonal bipyramid, and edges with two equivalent O(4)Mg2Fe3 trigonal bipyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1) and three equivalent Fe(2) atoms to form distorted OMg2Fe3 trigonal bipyramids that share  a cornercorner with one O(1)MgFe3 tetrahedra, edges with two equivalent O(1)MgFe3 tetrahedra, and edges with four equivalent O(4)Mg2Fe3 trigonal bipyramids. is represented by the CIF card [CIF]
data_Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.674
_cell_length_b   7.674
_cell_length_c   9.158
_cell_angle_alpha   56.526
_cell_angle_beta   56.526
_cell_angle_gamma   22.030
_symmetry_Int_Tables_number   1
_cell_volume   167.328
_cell_formula_units_Z   2
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  0.689  0.689  0.831  1.0
  Mg  Mg1  1  0.311  0.311  0.169  1.0
  Fe  Fe2  1  0.397  0.397  0.799  1.0
  Fe  Fe3  1  0.851  0.851  0.481  1.0
  Fe  Fe4  1  0.149  0.149  0.519  1.0
  Fe  Fe5  1  0.603  0.603  0.201  1.0
  O  O6  1  0.145  0.145  0.297  1.0
  O  O7  1  0.552  0.552  0.655  1.0
  O  O8  1  0.448  0.448  0.345  1.0
  O  O9  1  0.855  0.855  0.703  1.0
  O  O10  1  0.861  0.861  0.983  1.0
  O  O11  1  0.225  0.225  0.644  1.0
  O  O12  1  0.139  0.139  0.017  1.0
  O  O13  1  0.775  0.775  0.356  1.0
[/CIF]
.
The structure described by MgFe2O4 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form MgO5 trigonal bipyramids that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-61°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted FeO5 trigonal bipyramids that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°. In the second Fe site, Fe(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(4) atoms to form distorted FeO6 octahedra that share corners with four equivalent Mg(1)O5 trigonal bipyramids, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with four equivalent Fe(2)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(1) atoms to form OMgFe3 tetrahedra that share corners with two equivalent O(1)MgFe3 tetrahedra,  a cornercorner with one O(4)Mg2Fe3 trigonal bipyramid, and edges with two equivalent O(4)Mg2Fe3 trigonal bipyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1) and three equivalent Fe(2) atoms to form distorted OMg2Fe3 trigonal bipyramids that share  a cornercorner with one O(1)MgFe3 tetrahedra, edges with two equivalent O(1)MgFe3 tetrahedra, and edges with four equivalent O(4)Mg2Fe3 trigonal bipyramids. is represented by the CIF card [CIF]
data_Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.674
_cell_length_b   7.674
_cell_length_c   9.158
_cell_angle_alpha   56.526
_cell_angle_beta   56.526
_cell_angle_gamma   22.030
_symmetry_Int_Tables_number   1
_cell_volume   167.328
_cell_formula_units_Z   2
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  0.689  0.689  0.831  1.0
  Mg  Mg1  1  0.311  0.311  0.169  1.0
  Fe  Fe2  1  0.397  0.397  0.799  1.0
  Fe  Fe3  1  0.851  0.851  0.481  1.0
  Fe  Fe4  1  0.149  0.149  0.519  1.0
  Fe  Fe5  1  0.603  0.603  0.201  1.0
  O  O6  1  0.145  0.145  0.297  1.0
  O  O7  1  0.552  0.552  0.655  1.0
  O  O8  1  0.448  0.448  0.345  1.0
  O  O9  1  0.855  0.855  0.703  1.0
  O  O10  1  0.861  0.861  0.983  1.0
  O  O11  1  0.225  0.225  0.644  1.0
  O  O12  1  0.139  0.139  0.017  1.0
  O  O13  1  0.775  0.775  0.356  1.0
[/CIF]
.