The material described by MgFe2O4 is Spinel-like structured and crystallizes in the monoclinic Cm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(14), one O(3), and two equivalent O(1) atoms to form MgO4 tetrahedra that share  a cornercorner with one Mg(5)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Fe(7)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-59°. In the second Mg site, Mg(2) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(7) atoms to form MgO6 octahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(9)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. In the third Mg site, Mg(3) is bonded to one O(12), one O(8), two equivalent O(13), and two equivalent O(4) atoms to form MgO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra,  a cornercorner with one Fe(6)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(8)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra, and edges with four equivalent Fe(5)O6 octahedra. In the fourth Mg site, Mg(4) is bonded to one O(5), one O(9), two equivalent O(4), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(5)O6 octahedra. In the fifth Mg site, Mg(5) is bonded to one O(14), one O(17), two equivalent O(11), and two equivalent O(18) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(9)O4 tetrahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with four equivalent Fe(7)O6 octahedra. In the sixth Mg site, Mg(6) is bonded to one O(10), one O(15), two equivalent O(11), and two equivalent O(13) atoms to form MgO6 octahedra that share corners with three equivalent Fe(4)O4 tetrahedra, corners with three equivalent Fe(8)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. There are nine inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(9), and two equivalent O(4) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-60°. In the second Fe site, Fe(2) is bonded to one O(16), one O(3), two equivalent O(1), and two equivalent O(18) atoms to form FeO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Fe(9)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(9)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(15), one O(8), and two equivalent O(11) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Fe(5)O6 octahedra, corners with three equivalent Mg(6)O6 octahedra, and corners with four equivalent Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-59°. In the fifth Fe site, Fe(5) is bonded to one O(10), one O(12), one O(13), one O(4), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra,  a cornercorner with one Fe(6)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(8)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, and edges with two equivalent Fe(5)O6 octahedra. In the sixth Fe site, Fe(6) is bonded to one O(12), one O(5), and two equivalent O(7) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Fe(5)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(14), one O(15), one O(16), one O(17), and one O(18) atom to form FeO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(9)O4 tetrahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. In the eighth Fe site, Fe(8) is bonded to one O(10), one O(17), and two equivalent O(13) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(5)O6 octahedra, corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Fe(7)O6 octahedra, corners with three equivalent Mg(6)O6 octahedra, and corners with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the ninth Fe site, Fe(9) is bonded to one O(16), one O(6), and two equivalent O(18) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and corners with four equivalent Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Fe(1), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Mg(4), one Fe(1), and one Fe(5) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Mg(4), one Fe(6), and two equivalent Fe(3) atoms. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(2), one Fe(9), and two equivalent Fe(3) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Mg(4), one Fe(3), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Fe(4), and two equivalent Fe(5) atoms. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Mg(4), one Fe(1), and two equivalent Fe(5) atoms. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(6), one Fe(8), and two equivalent Fe(5) atoms. In the eleventh O site, O(11) is bonded in a rectangular see-saw-like geometry to one Mg(5), one Mg(6), one Fe(4), and one Fe(7) atom. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Fe(6), and two equivalent Fe(5) atoms. In the thirteenth O site, O(13) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Mg(6), one Fe(5), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded to one Mg(1), one Mg(5), and two equivalent Fe(7) atoms to form distorted OMg2Fe2 trigonal pyramids that share corners with two equivalent O(16)Fe4 trigonal pyramids and corners with four equivalent O(18)MgFe3 trigonal pyramids. In the fifteenth O site, O(15) is bonded in a rectangular see-saw-like geometry to one Mg(6), one Fe(4), and two equivalent Fe(7) atoms. In the sixteenth O site, O(16) is bonded to one Fe(2), one Fe(9), and two equivalent Fe(7) atoms to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(14)Mg2Fe2 trigonal pyramids, corners with two equivalent O(18)MgFe3 trigonal pyramids, and edges with two equivalent O(18)MgFe3 trigonal pyramids. In the seventeenth O site, O(17) is bonded in a distorted rectangular see-saw-like geometry to one Mg(5), one Fe(8), and two equivalent Fe(7) atoms. In the eighteenth O site, O(18) is bonded to one Mg(5), one Fe(2), one Fe(7), and one Fe(9) atom to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(16)Fe4 trigonal pyramid,  a cornercorner with one O(18)MgFe3 trigonal pyramid, corners with two equivalent O(14)Mg2Fe2 trigonal pyramids,  an edgeedge with one O(16)Fe4 trigonal pyramid, and  an edgeedge with one O(18)MgFe3 trigonal pyramid. is represented by the CIF card [CIF]
data_Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.983
_cell_length_b   5.983
_cell_length_c   14.631
_cell_angle_alpha   89.979
_cell_angle_beta   89.979
_cell_angle_gamma   60.221
_symmetry_Int_Tables_number   1
_cell_volume   454.507
_cell_formula_units_Z   6
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  0.163  0.163  0.958  1.0
  Mg  Mg1  1  0.666  0.666  0.832  1.0
  Mg  Mg2  1  0.000  0.000  0.500  1.0
  Mg  Mg3  1  0.831  0.831  0.665  1.0
  Mg  Mg4  1  0.333  0.333  0.168  1.0
  Mg  Mg5  1  0.169  0.169  0.336  1.0
  Fe  Fe6  1  0.495  0.495  0.618  1.0
  Fe  Fe7  1  0.501  0.501  0.996  1.0
  Fe  Fe8  1  0.667  0.170  0.832  1.0
  Fe  Fe9  1  0.827  0.827  0.294  1.0
  Fe  Fe10  1  0.170  0.667  0.832  1.0
  Fe  Fe11  1  1.000  0.500  0.500  1.0
  Fe  Fe12  1  0.500  1.000  0.500  1.0
  Fe  Fe13  1  0.173  0.173  0.708  1.0
  Fe  Fe14  1  0.331  0.838  0.169  1.0
  Fe  Fe15  1  0.838  0.331  0.169  1.0
  Fe  Fe16  1  0.505  0.505  0.380  1.0
  Fe  Fe17  1  0.838  0.838  0.041  1.0
  O  O18  1  0.342  0.804  0.913  1.0
  O  O19  1  0.804  0.342  0.913  1.0
  O  O20  1  0.497  0.497  0.752  1.0
  O  O21  1  0.345  0.345  0.912  1.0
  O  O22  1  0.665  0.145  0.577  1.0
  O  O23  1  0.994  0.994  0.752  1.0
  O  O24  1  0.836  0.836  0.910  1.0
  O  O25  1  0.517  0.996  0.753  1.0
  O  O26  1  0.145  0.665  0.577  1.0
  O  O27  1  0.826  0.826  0.427  1.0
  O  O28  1  0.674  0.674  0.574  1.0
  O  O29  1  0.996  0.517  0.753  1.0
  O  O30  1  0.326  0.326  0.425  1.0
  O  O31  1  0.004  0.484  0.248  1.0
  O  O32  1  0.174  0.174  0.574  1.0
  O  O33  1  0.853  0.335  0.422  1.0
  O  O34  1  0.484  0.004  0.248  1.0
  O  O35  1  0.162  0.162  0.095  1.0
  O  O36  1  0.335  0.853  0.422  1.0
  O  O37  1  0.006  0.006  0.249  1.0
  O  O38  1  0.658  0.658  0.086  1.0
  O  O39  1  0.503  0.503  0.245  1.0
  O  O40  1  0.188  0.659  0.085  1.0
  O  O41  1  0.659  0.188  0.085  1.0
[/CIF]
.
The material described by MgFe2O4 is Spinel-like structured and crystallizes in the monoclinic Cm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(14), one O(3), and two equivalent O(1) atoms to form MgO4 tetrahedra that share  a cornercorner with one Mg(5)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Fe(7)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-59°. In the second Mg site, Mg(2) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(7) atoms to form MgO6 octahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(9)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. In the third Mg site, Mg(3) is bonded to one O(12), one O(8), two equivalent O(13), and two equivalent O(4) atoms to form MgO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra,  a cornercorner with one Fe(6)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(8)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra, and edges with four equivalent Fe(5)O6 octahedra. In the fourth Mg site, Mg(4) is bonded to one O(5), one O(9), two equivalent O(4), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with three equivalent Fe(1)O4 tetrahedra, corners with three equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(3)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(5)O6 octahedra. In the fifth Mg site, Mg(5) is bonded to one O(14), one O(17), two equivalent O(11), and two equivalent O(18) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(9)O4 tetrahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with four equivalent Fe(7)O6 octahedra. In the sixth Mg site, Mg(6) is bonded to one O(10), one O(15), two equivalent O(11), and two equivalent O(13) atoms to form MgO6 octahedra that share corners with three equivalent Fe(4)O4 tetrahedra, corners with three equivalent Fe(8)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. There are nine inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(9), and two equivalent O(4) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-60°. In the second Fe site, Fe(2) is bonded to one O(16), one O(3), two equivalent O(1), and two equivalent O(18) atoms to form FeO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Fe(9)O4 tetrahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Mg(5)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(9)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Fe(6)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(15), one O(8), and two equivalent O(11) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Fe(5)O6 octahedra, corners with three equivalent Mg(6)O6 octahedra, and corners with four equivalent Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-59°. In the fifth Fe site, Fe(5) is bonded to one O(10), one O(12), one O(13), one O(4), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra,  a cornercorner with one Fe(6)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(8)O4 tetrahedra,  an edgeedge with one Mg(4)O6 octahedra,  an edgeedge with one Mg(6)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, and edges with two equivalent Fe(5)O6 octahedra. In the sixth Fe site, Fe(6) is bonded to one O(12), one O(5), and two equivalent O(7) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(3)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Fe(5)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(14), one O(15), one O(16), one O(17), and one O(18) atom to form FeO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(4)O4 tetrahedra, corners with two equivalent Fe(9)O4 tetrahedra,  an edgeedge with one Mg(6)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. In the eighth Fe site, Fe(8) is bonded to one O(10), one O(17), and two equivalent O(13) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(5)O6 octahedra, corners with two equivalent Mg(3)O6 octahedra, corners with two equivalent Fe(7)O6 octahedra, corners with three equivalent Mg(6)O6 octahedra, and corners with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the ninth Fe site, Fe(9) is bonded to one O(16), one O(6), and two equivalent O(18) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Mg(5)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and corners with four equivalent Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Fe(1), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Mg(4), one Fe(1), and one Fe(5) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Mg(4), one Fe(6), and two equivalent Fe(3) atoms. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(2), one Fe(9), and two equivalent Fe(3) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Mg(4), one Fe(3), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Fe(4), and two equivalent Fe(5) atoms. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Mg(4), one Fe(1), and two equivalent Fe(5) atoms. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(6), one Fe(8), and two equivalent Fe(5) atoms. In the eleventh O site, O(11) is bonded in a rectangular see-saw-like geometry to one Mg(5), one Mg(6), one Fe(4), and one Fe(7) atom. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Fe(6), and two equivalent Fe(5) atoms. In the thirteenth O site, O(13) is bonded in a rectangular see-saw-like geometry to one Mg(3), one Mg(6), one Fe(5), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded to one Mg(1), one Mg(5), and two equivalent Fe(7) atoms to form distorted OMg2Fe2 trigonal pyramids that share corners with two equivalent O(16)Fe4 trigonal pyramids and corners with four equivalent O(18)MgFe3 trigonal pyramids. In the fifteenth O site, O(15) is bonded in a rectangular see-saw-like geometry to one Mg(6), one Fe(4), and two equivalent Fe(7) atoms. In the sixteenth O site, O(16) is bonded to one Fe(2), one Fe(9), and two equivalent Fe(7) atoms to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(14)Mg2Fe2 trigonal pyramids, corners with two equivalent O(18)MgFe3 trigonal pyramids, and edges with two equivalent O(18)MgFe3 trigonal pyramids. In the seventeenth O site, O(17) is bonded in a distorted rectangular see-saw-like geometry to one Mg(5), one Fe(8), and two equivalent Fe(7) atoms. In the eighteenth O site, O(18) is bonded to one Mg(5), one Fe(2), one Fe(7), and one Fe(9) atom to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(16)Fe4 trigonal pyramid,  a cornercorner with one O(18)MgFe3 trigonal pyramid, corners with two equivalent O(14)Mg2Fe2 trigonal pyramids,  an edgeedge with one O(16)Fe4 trigonal pyramid, and  an edgeedge with one O(18)MgFe3 trigonal pyramid. is represented by the CIF card [CIF]
data_Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.983
_cell_length_b   5.983
_cell_length_c   14.631
_cell_angle_alpha   89.979
_cell_angle_beta   89.979
_cell_angle_gamma   60.221
_symmetry_Int_Tables_number   1
_cell_volume   454.507
_cell_formula_units_Z   6
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  0.163  0.163  0.958  1.0
  Mg  Mg1  1  0.666  0.666  0.832  1.0
  Mg  Mg2  1  0.000  0.000  0.500  1.0
  Mg  Mg3  1  0.831  0.831  0.665  1.0
  Mg  Mg4  1  0.333  0.333  0.168  1.0
  Mg  Mg5  1  0.169  0.169  0.336  1.0
  Fe  Fe6  1  0.495  0.495  0.618  1.0
  Fe  Fe7  1  0.501  0.501  0.996  1.0
  Fe  Fe8  1  0.667  0.170  0.832  1.0
  Fe  Fe9  1  0.827  0.827  0.294  1.0
  Fe  Fe10  1  0.170  0.667  0.832  1.0
  Fe  Fe11  1  1.000  0.500  0.500  1.0
  Fe  Fe12  1  0.500  1.000  0.500  1.0
  Fe  Fe13  1  0.173  0.173  0.708  1.0
  Fe  Fe14  1  0.331  0.838  0.169  1.0
  Fe  Fe15  1  0.838  0.331  0.169  1.0
  Fe  Fe16  1  0.505  0.505  0.380  1.0
  Fe  Fe17  1  0.838  0.838  0.041  1.0
  O  O18  1  0.342  0.804  0.913  1.0
  O  O19  1  0.804  0.342  0.913  1.0
  O  O20  1  0.497  0.497  0.752  1.0
  O  O21  1  0.345  0.345  0.912  1.0
  O  O22  1  0.665  0.145  0.577  1.0
  O  O23  1  0.994  0.994  0.752  1.0
  O  O24  1  0.836  0.836  0.910  1.0
  O  O25  1  0.517  0.996  0.753  1.0
  O  O26  1  0.145  0.665  0.577  1.0
  O  O27  1  0.826  0.826  0.427  1.0
  O  O28  1  0.674  0.674  0.574  1.0
  O  O29  1  0.996  0.517  0.753  1.0
  O  O30  1  0.326  0.326  0.425  1.0
  O  O31  1  0.004  0.484  0.248  1.0
  O  O32  1  0.174  0.174  0.574  1.0
  O  O33  1  0.853  0.335  0.422  1.0
  O  O34  1  0.484  0.004  0.248  1.0
  O  O35  1  0.162  0.162  0.095  1.0
  O  O36  1  0.335  0.853  0.422  1.0
  O  O37  1  0.006  0.006  0.249  1.0
  O  O38  1  0.658  0.658  0.086  1.0
  O  O39  1  0.503  0.503  0.245  1.0
  O  O40  1  0.188  0.659  0.085  1.0
  O  O41  1  0.659  0.188  0.085  1.0
[/CIF]
.