The material structure described by MgFe7(Ni3O8)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(11), one O(7), two equivalent O(10), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Ni(4)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, edges with two equivalent Ni(5)O6 octahedra, and edges with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-4°. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(7), two equivalent O(4), and two equivalent O(9) atoms to form FeO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second Fe site, Fe(2) is bonded in a rectangular see-saw-like geometry to one O(6), one O(7), and two equivalent O(9) atoms. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with three equivalent Ni(3)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-6°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(12), and two equivalent O(4) atoms to form FeO4 tetrahedra that share  a cornercorner with one Ni(5)O6 octahedra, corners with two equivalent Fe(5)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-63°. In the fifth Fe site, Fe(5) is bonded to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom to form FeO6 octahedra that share corners with three equivalent Ni(3)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, and edges with two equivalent Ni(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with three equivalent Ni(2)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the second Ni site, Ni(2) is bonded to one O(2), one O(8), two equivalent O(10), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(5)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra, and edges with four equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the third Ni site, Ni(3) is bonded to one O(10), one O(11), one O(2), one O(3), one O(5), and one O(8) atom to form NiO6 octahedra that share corners with three equivalent Fe(3)O6 octahedra, corners with three equivalent Fe(5)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra,  an edgeedge with one Fe(5)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(5), two equivalent O(10), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the fifth Ni site, Ni(5) is bonded to one O(12), one O(8), two equivalent O(10), and two equivalent O(9) atoms to form NiO6 octahedra that share corners with three equivalent Ni(2)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-4°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(4), and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded to two equivalent Fe(3), one Ni(1), one Ni(2), and two equivalent Ni(3) atoms to form OFe2Ni4 octahedra that share corners with three equivalent O(8)Fe2Ni4 octahedra, corners with three equivalent O(6)Fe3Ni tetrahedra,  an edgeedge with one O(11)MgFe2Ni3 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra, edges with two equivalent O(5)Fe2Ni3 square pyramids, and edges with four equivalent O(3)FeNi4 square pyramids. The corner-sharing octahedral tilt angles range from 2-4°. In the third O site, O(3) is bonded to one Fe(3), one Ni(1), one Ni(2), one Ni(3), and one Ni(4) atom to form OFeNi4 square pyramids that share corners with three equivalent O(10)MgFeNi4 octahedra,  a cornercorner with one O(5)Fe2Ni3 square pyramid,  a cornercorner with one O(3)FeNi4 square pyramid,  an edgeedge with one O(8)Fe2Ni4 octahedra,  an edgeedge with one O(11)MgFe2Ni3 octahedra,  an edgeedge with one O(10)MgFeNi4 octahedra, edges with two equivalent O(2)Fe2Ni4 octahedra,  an edgeedge with one O(5)Fe2Ni3 square pyramid,  an edgeedge with one O(3)FeNi4 square pyramid, and  an edgeedge with one O(6)Fe3Ni tetrahedra. The corner-sharing octahedral tilt angles range from 2-5°. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Fe(1), one Fe(3), one Fe(4), and one Ni(1) atom. In the fifth O site, O(5) is bonded to two equivalent Fe(3), one Ni(4), and two equivalent Ni(3) atoms to form OFe2Ni3 square pyramids that share corners with three equivalent O(11)MgFe2Ni3 octahedra, corners with two equivalent O(3)FeNi4 square pyramids,  an edgeedge with one O(8)Fe2Ni4 octahedra, edges with two equivalent O(2)Fe2Ni4 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra, edges with two equivalent O(3)FeNi4 square pyramids, and  an edgeedge with one O(6)Fe3Ni tetrahedra. The corner-sharing octahedral tilt angles range from 3-5°. In the sixth O site, O(6) is bonded to one Fe(2), two equivalent Fe(3), and one Ni(1) atom to form distorted OFe3Ni tetrahedra that share corners with three equivalent O(2)Fe2Ni4 octahedra,  a cornercorner with one O(7)MgFe4 trigonal bipyramid, corners with two equivalent O(9)MgFe3Ni trigonal bipyramids,  an edgeedge with one O(5)Fe2Ni3 square pyramid, and edges with two equivalent O(3)FeNi4 square pyramids. The corner-sharing octahedral tilt angles range from 4-7°. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(1), one Fe(2), and two equivalent Fe(5) atoms to form OMgFe4 trigonal bipyramids that share corners with three equivalent O(11)MgFe2Ni3 octahedra,  a cornercorner with one O(6)Fe3Ni tetrahedra,  an edgeedge with one O(8)Fe2Ni4 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra, and edges with four equivalent O(9)MgFe3Ni trigonal bipyramids. The corner-sharing octahedral tilt angles range from 7-11°. In the eighth O site, O(8) is bonded to two equivalent Fe(5), one Ni(2), one Ni(5), and two equivalent Ni(3) atoms to form OFe2Ni4 octahedra that share corners with three equivalent O(2)Fe2Ni4 octahedra, edges with two equivalent O(11)MgFe2Ni3 octahedra, edges with four equivalent O(10)MgFeNi4 octahedra,  an edgeedge with one O(5)Fe2Ni3 square pyramid, edges with two equivalent O(3)FeNi4 square pyramids,  an edgeedge with one O(7)MgFe4 trigonal bipyramid, and edges with two equivalent O(9)MgFe3Ni trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-4°. In the ninth O site, O(9) is bonded to one Mg(1), one Fe(1), one Fe(2), one Fe(5), and one Ni(5) atom to form OMgFe3Ni trigonal bipyramids that share corners with three equivalent O(10)MgFeNi4 octahedra,  a cornercorner with one O(6)Fe3Ni tetrahedra,  an edgeedge with one O(8)Fe2Ni4 octahedra,  an edgeedge with one O(11)MgFe2Ni3 octahedra,  an edgeedge with one O(10)MgFeNi4 octahedra, edges with two equivalent O(9)MgFe3Ni trigonal bipyramids, and edges with two equivalent O(7)MgFe4 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 7-10°. In the tenth O site, O(10) is bonded to one Mg(1), one Fe(5), one Ni(2), one Ni(3), one Ni(4), and one Ni(5) atom to form OMgFeNi4 octahedra that share corners with three equivalent O(3)FeNi4 square pyramids, corners with three equivalent O(9)MgFe3Ni trigonal bipyramids,  an edgeedge with one O(2)Fe2Ni4 octahedra, edges with two equivalent O(8)Fe2Ni4 octahedra, edges with two equivalent O(11)MgFe2Ni3 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra,  an edgeedge with one O(5)Fe2Ni3 square pyramid,  an edgeedge with one O(3)FeNi4 square pyramid,  an edgeedge with one O(9)MgFe3Ni trigonal bipyramid, and  an edgeedge with one O(7)MgFe4 trigonal bipyramid. In the eleventh O site, O(11) is bonded to one Mg(1), two equivalent Fe(5), one Ni(4), and two equivalent Ni(3) atoms to form OMgFe2Ni3 octahedra that share corners with three equivalent O(5)Fe2Ni3 square pyramids, corners with three equivalent O(7)MgFe4 trigonal bipyramids,  an edgeedge with one O(2)Fe2Ni4 octahedra, edges with two equivalent O(8)Fe2Ni4 octahedra, edges with four equivalent O(10)MgFeNi4 octahedra, edges with two equivalent O(3)FeNi4 square pyramids, and edges with two equivalent O(9)MgFe3Ni trigonal bipyramids. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Fe(4), two equivalent Fe(5), and one Ni(5) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe7(Ni3O8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.017
_cell_length_b   6.017
_cell_length_c   10.635
_cell_angle_alpha   106.446
_cell_angle_beta   73.554
_cell_angle_gamma   120.001
_symmetry_Int_Tables_number   1
_cell_volume   315.165
_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  0.070  0.930  0.781  1.0
  Fe  Fe1  1  0.322  0.678  0.054  1.0
  Fe  Fe2  1  0.992  0.008  0.032  1.0
  Fe  Fe3  1  0.566  0.937  0.318  1.0
  Fe  Fe4  1  0.063  0.434  0.318  1.0
  Fe  Fe5  1  0.629  0.371  0.131  1.0
  Fe  Fe6  1  0.563  0.949  0.818  1.0
  Fe  Fe7  1  0.051  0.437  0.818  1.0
  Ni  Ni8  1  0.064  0.936  0.314  1.0
  Ni  Ni9  1  0.318  0.682  0.558  1.0
  Ni  Ni10  1  0.799  0.682  0.555  1.0
  Ni  Ni11  1  0.318  0.201  0.555  1.0
  Ni  Ni12  1  0.810  0.190  0.562  1.0
  Ni  Ni13  1  0.564  0.436  0.812  1.0
  O  O14  1  0.430  0.570  0.201  1.0
  O  O15  1  0.192  0.808  0.433  1.0
  O  O16  1  0.687  0.830  0.442  1.0
  O  O17  1  0.170  0.313  0.442  1.0
  O  O18  1  0.958  0.564  0.193  1.0
  O  O19  1  0.436  0.042  0.193  1.0
  O  O20  1  0.693  0.307  0.438  1.0
  O  O21  1  0.926  0.074  0.222  1.0
  O  O22  1  0.191  0.809  0.914  1.0
  O  O23  1  0.436  0.564  0.683  1.0
  O  O24  1  0.695  0.807  0.917  1.0
  O  O25  1  0.193  0.305  0.917  1.0
  O  O26  1  0.936  0.561  0.679  1.0
  O  O27  1  0.439  0.064  0.679  1.0
  O  O28  1  0.937  0.063  0.679  1.0
  O  O29  1  0.688  0.312  0.934  1.0
[/CIF]
.
The material structure described by MgFe7(Ni3O8)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(11), one O(7), two equivalent O(10), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Ni(4)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, edges with two equivalent Ni(5)O6 octahedra, and edges with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-4°. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(7), two equivalent O(4), and two equivalent O(9) atoms to form FeO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second Fe site, Fe(2) is bonded in a rectangular see-saw-like geometry to one O(6), one O(7), and two equivalent O(9) atoms. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with three equivalent Ni(3)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-6°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(12), and two equivalent O(4) atoms to form FeO4 tetrahedra that share  a cornercorner with one Ni(5)O6 octahedra, corners with two equivalent Fe(5)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-63°. In the fifth Fe site, Fe(5) is bonded to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom to form FeO6 octahedra that share corners with three equivalent Ni(3)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, and edges with two equivalent Ni(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with three equivalent Ni(2)O6 octahedra, corners with two equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the second Ni site, Ni(2) is bonded to one O(2), one O(8), two equivalent O(10), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(5)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra, and edges with four equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-7°. In the third Ni site, Ni(3) is bonded to one O(10), one O(11), one O(2), one O(3), one O(5), and one O(8) atom to form NiO6 octahedra that share corners with three equivalent Fe(3)O6 octahedra, corners with three equivalent Fe(5)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra,  an edgeedge with one Fe(5)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(5), two equivalent O(10), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(5)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the fifth Ni site, Ni(5) is bonded to one O(12), one O(8), two equivalent O(10), and two equivalent O(9) atoms to form NiO6 octahedra that share corners with three equivalent Ni(2)O6 octahedra,  a cornercorner with one Fe(4)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-4°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(4), and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded to two equivalent Fe(3), one Ni(1), one Ni(2), and two equivalent Ni(3) atoms to form OFe2Ni4 octahedra that share corners with three equivalent O(8)Fe2Ni4 octahedra, corners with three equivalent O(6)Fe3Ni tetrahedra,  an edgeedge with one O(11)MgFe2Ni3 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra, edges with two equivalent O(5)Fe2Ni3 square pyramids, and edges with four equivalent O(3)FeNi4 square pyramids. The corner-sharing octahedral tilt angles range from 2-4°. In the third O site, O(3) is bonded to one Fe(3), one Ni(1), one Ni(2), one Ni(3), and one Ni(4) atom to form OFeNi4 square pyramids that share corners with three equivalent O(10)MgFeNi4 octahedra,  a cornercorner with one O(5)Fe2Ni3 square pyramid,  a cornercorner with one O(3)FeNi4 square pyramid,  an edgeedge with one O(8)Fe2Ni4 octahedra,  an edgeedge with one O(11)MgFe2Ni3 octahedra,  an edgeedge with one O(10)MgFeNi4 octahedra, edges with two equivalent O(2)Fe2Ni4 octahedra,  an edgeedge with one O(5)Fe2Ni3 square pyramid,  an edgeedge with one O(3)FeNi4 square pyramid, and  an edgeedge with one O(6)Fe3Ni tetrahedra. The corner-sharing octahedral tilt angles range from 2-5°. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Fe(1), one Fe(3), one Fe(4), and one Ni(1) atom. In the fifth O site, O(5) is bonded to two equivalent Fe(3), one Ni(4), and two equivalent Ni(3) atoms to form OFe2Ni3 square pyramids that share corners with three equivalent O(11)MgFe2Ni3 octahedra, corners with two equivalent O(3)FeNi4 square pyramids,  an edgeedge with one O(8)Fe2Ni4 octahedra, edges with two equivalent O(2)Fe2Ni4 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra, edges with two equivalent O(3)FeNi4 square pyramids, and  an edgeedge with one O(6)Fe3Ni tetrahedra. The corner-sharing octahedral tilt angles range from 3-5°. In the sixth O site, O(6) is bonded to one Fe(2), two equivalent Fe(3), and one Ni(1) atom to form distorted OFe3Ni tetrahedra that share corners with three equivalent O(2)Fe2Ni4 octahedra,  a cornercorner with one O(7)MgFe4 trigonal bipyramid, corners with two equivalent O(9)MgFe3Ni trigonal bipyramids,  an edgeedge with one O(5)Fe2Ni3 square pyramid, and edges with two equivalent O(3)FeNi4 square pyramids. The corner-sharing octahedral tilt angles range from 4-7°. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(1), one Fe(2), and two equivalent Fe(5) atoms to form OMgFe4 trigonal bipyramids that share corners with three equivalent O(11)MgFe2Ni3 octahedra,  a cornercorner with one O(6)Fe3Ni tetrahedra,  an edgeedge with one O(8)Fe2Ni4 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra, and edges with four equivalent O(9)MgFe3Ni trigonal bipyramids. The corner-sharing octahedral tilt angles range from 7-11°. In the eighth O site, O(8) is bonded to two equivalent Fe(5), one Ni(2), one Ni(5), and two equivalent Ni(3) atoms to form OFe2Ni4 octahedra that share corners with three equivalent O(2)Fe2Ni4 octahedra, edges with two equivalent O(11)MgFe2Ni3 octahedra, edges with four equivalent O(10)MgFeNi4 octahedra,  an edgeedge with one O(5)Fe2Ni3 square pyramid, edges with two equivalent O(3)FeNi4 square pyramids,  an edgeedge with one O(7)MgFe4 trigonal bipyramid, and edges with two equivalent O(9)MgFe3Ni trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-4°. In the ninth O site, O(9) is bonded to one Mg(1), one Fe(1), one Fe(2), one Fe(5), and one Ni(5) atom to form OMgFe3Ni trigonal bipyramids that share corners with three equivalent O(10)MgFeNi4 octahedra,  a cornercorner with one O(6)Fe3Ni tetrahedra,  an edgeedge with one O(8)Fe2Ni4 octahedra,  an edgeedge with one O(11)MgFe2Ni3 octahedra,  an edgeedge with one O(10)MgFeNi4 octahedra, edges with two equivalent O(9)MgFe3Ni trigonal bipyramids, and edges with two equivalent O(7)MgFe4 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 7-10°. In the tenth O site, O(10) is bonded to one Mg(1), one Fe(5), one Ni(2), one Ni(3), one Ni(4), and one Ni(5) atom to form OMgFeNi4 octahedra that share corners with three equivalent O(3)FeNi4 square pyramids, corners with three equivalent O(9)MgFe3Ni trigonal bipyramids,  an edgeedge with one O(2)Fe2Ni4 octahedra, edges with two equivalent O(8)Fe2Ni4 octahedra, edges with two equivalent O(11)MgFe2Ni3 octahedra, edges with two equivalent O(10)MgFeNi4 octahedra,  an edgeedge with one O(5)Fe2Ni3 square pyramid,  an edgeedge with one O(3)FeNi4 square pyramid,  an edgeedge with one O(9)MgFe3Ni trigonal bipyramid, and  an edgeedge with one O(7)MgFe4 trigonal bipyramid. In the eleventh O site, O(11) is bonded to one Mg(1), two equivalent Fe(5), one Ni(4), and two equivalent Ni(3) atoms to form OMgFe2Ni3 octahedra that share corners with three equivalent O(5)Fe2Ni3 square pyramids, corners with three equivalent O(7)MgFe4 trigonal bipyramids,  an edgeedge with one O(2)Fe2Ni4 octahedra, edges with two equivalent O(8)Fe2Ni4 octahedra, edges with four equivalent O(10)MgFeNi4 octahedra, edges with two equivalent O(3)FeNi4 square pyramids, and edges with two equivalent O(9)MgFe3Ni trigonal bipyramids. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Fe(4), two equivalent Fe(5), and one Ni(5) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe7(Ni3O8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.017
_cell_length_b   6.017
_cell_length_c   10.635
_cell_angle_alpha   106.446
_cell_angle_beta   73.554
_cell_angle_gamma   120.001
_symmetry_Int_Tables_number   1
_cell_volume   315.165
_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  0.070  0.930  0.781  1.0
  Fe  Fe1  1  0.322  0.678  0.054  1.0
  Fe  Fe2  1  0.992  0.008  0.032  1.0
  Fe  Fe3  1  0.566  0.937  0.318  1.0
  Fe  Fe4  1  0.063  0.434  0.318  1.0
  Fe  Fe5  1  0.629  0.371  0.131  1.0
  Fe  Fe6  1  0.563  0.949  0.818  1.0
  Fe  Fe7  1  0.051  0.437  0.818  1.0
  Ni  Ni8  1  0.064  0.936  0.314  1.0
  Ni  Ni9  1  0.318  0.682  0.558  1.0
  Ni  Ni10  1  0.799  0.682  0.555  1.0
  Ni  Ni11  1  0.318  0.201  0.555  1.0
  Ni  Ni12  1  0.810  0.190  0.562  1.0
  Ni  Ni13  1  0.564  0.436  0.812  1.0
  O  O14  1  0.430  0.570  0.201  1.0
  O  O15  1  0.192  0.808  0.433  1.0
  O  O16  1  0.687  0.830  0.442  1.0
  O  O17  1  0.170  0.313  0.442  1.0
  O  O18  1  0.958  0.564  0.193  1.0
  O  O19  1  0.436  0.042  0.193  1.0
  O  O20  1  0.693  0.307  0.438  1.0
  O  O21  1  0.926  0.074  0.222  1.0
  O  O22  1  0.191  0.809  0.914  1.0
  O  O23  1  0.436  0.564  0.683  1.0
  O  O24  1  0.695  0.807  0.917  1.0
  O  O25  1  0.193  0.305  0.917  1.0
  O  O26  1  0.936  0.561  0.679  1.0
  O  O27  1  0.439  0.064  0.679  1.0
  O  O28  1  0.937  0.063  0.679  1.0
  O  O29  1  0.688  0.312  0.934  1.0
[/CIF]
.