The material structure described by MgFe8(OF)8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(7), one F(3), one F(4), and one F(6) atom to form distorted MgO3F3 octahedra that share corners with two equivalent Fe(6)O3F3 octahedra,  a cornercorner with one Fe(3)O3F2 trigonal bipyramid,  an edgeedge with one Fe(3)O3F2 trigonal bipyramid, and faces with two equivalent Fe(8)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-48°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(8), one F(1), and one F(8) atom to form edge-sharing FeO3F2 trigonal bipyramids. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(8), one F(1), one F(4), and one F(6) atom. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(7), one F(6), and one F(7) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with three equivalent Fe(6)O3F3 octahedra, corners with three equivalent Fe(8)O3F3 octahedra,  an edgeedge with one Mg(1)O3F3 octahedra, and  an edgeedge with one Fe(4)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 40-65°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(5), one F(7), and one F(8) atom to form distorted FeO3F2 trigonal bipyramids that share corners with three equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(1)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 46-54°. In the fifth Fe site, Fe(5) is bonded in a 6-coordinate geometry to one O(4), one O(6), one O(8), one F(1), one F(2), and one F(4) atom. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(7), one F(3), one F(5), and one F(7) atom to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with three equivalent Fe(3)O3F2 trigonal bipyramids, corners with three equivalent Fe(4)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(8)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-48°. In the seventh Fe site, Fe(7) is bonded in a 5-coordinate geometry to one O(3), one O(5), one O(6), one F(2), and one F(5) atom. In the eighth Fe site, Fe(8) is bonded to one O(1), one O(4), one O(7), one F(3), one F(4), and one F(6) atom to form distorted FeO3F3 octahedra that share corners with three equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(6)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing OMgFe3 tetrahedra. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing OMgFe3 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(3), one Fe(6), and one Fe(8) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the second F site, F(2) is bonded in a water-like geometry to one Fe(5) and one Fe(7) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(6), and one Fe(8) atom. In the fourth F site, F(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom. In the fifth F site, F(5) is bonded in an L-shaped geometry to one Fe(6) and one Fe(7) atom. In the sixth F site, F(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom. In the seventh F site, F(7) is bonded in a distorted L-shaped geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the eighth F site, F(8) is bonded in a distorted water-like geometry to one Fe(1) and one Fe(4) atom. is represented by the CIF file [CIF]
data_MgFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.190
_cell_length_b   5.095
_cell_length_c   11.827
_cell_angle_alpha   89.750
_cell_angle_beta   88.249
_cell_angle_gamma   87.420
_symmetry_Int_Tables_number   1
_cell_volume   312.303
_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  0.502  0.014  0.367  1.0
  Fe  Fe1  1  0.932  0.919  0.995  1.0
  Fe  Fe2  1  0.047  0.036  0.236  1.0
  Fe  Fe3  1  0.959  0.917  0.508  1.0
  Fe  Fe4  1  0.097  0.059  0.751  1.0
  Fe  Fe5  1  0.554  0.432  0.120  1.0
  Fe  Fe6  1  0.466  0.547  0.623  1.0
  Fe  Fe7  1  0.454  0.549  0.875  1.0
  Fe  Fe8  1  0.448  0.527  0.372  1.0
  O  O9  1  0.171  0.832  0.377  1.0
  O  O10  1  0.177  0.803  0.628  1.0
  O  O11  1  0.182  0.819  0.873  1.0
  O  O12  1  0.372  0.278  0.249  1.0
  O  O13  1  0.340  0.330  0.749  1.0
  O  O14  1  0.668  0.668  0.996  1.0
  O  O15  1  0.646  0.731  0.494  1.0
  O  O16  1  0.837  0.180  0.110  1.0
  F  F17  1  0.171  0.759  0.111  1.0
  F  F18  1  0.342  0.299  0.996  1.0
  F  F19  1  0.351  0.283  0.507  1.0
  F  F20  1  0.659  0.734  0.247  1.0
  F  F21  1  0.664  0.701  0.745  1.0
  F  F22  1  0.811  0.206  0.391  1.0
  F  F23  1  0.851  0.199  0.625  1.0
  F  F24  1  0.826  0.178  0.866  1.0
[/CIF]
.
The material structure described by MgFe8(OF)8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(7), one F(3), one F(4), and one F(6) atom to form distorted MgO3F3 octahedra that share corners with two equivalent Fe(6)O3F3 octahedra,  a cornercorner with one Fe(3)O3F2 trigonal bipyramid,  an edgeedge with one Fe(3)O3F2 trigonal bipyramid, and faces with two equivalent Fe(8)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-48°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(8), one F(1), and one F(8) atom to form edge-sharing FeO3F2 trigonal bipyramids. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(8), one F(1), one F(4), and one F(6) atom. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(7), one F(6), and one F(7) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with three equivalent Fe(6)O3F3 octahedra, corners with three equivalent Fe(8)O3F3 octahedra,  an edgeedge with one Mg(1)O3F3 octahedra, and  an edgeedge with one Fe(4)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 40-65°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(5), one F(7), and one F(8) atom to form distorted FeO3F2 trigonal bipyramids that share corners with three equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(1)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 46-54°. In the fifth Fe site, Fe(5) is bonded in a 6-coordinate geometry to one O(4), one O(6), one O(8), one F(1), one F(2), and one F(4) atom. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(7), one F(3), one F(5), and one F(7) atom to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with three equivalent Fe(3)O3F2 trigonal bipyramids, corners with three equivalent Fe(4)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(8)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-48°. In the seventh Fe site, Fe(7) is bonded in a 5-coordinate geometry to one O(3), one O(5), one O(6), one F(2), and one F(5) atom. In the eighth Fe site, Fe(8) is bonded to one O(1), one O(4), one O(7), one F(3), one F(4), and one F(6) atom to form distorted FeO3F3 octahedra that share corners with three equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(6)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing OMgFe3 tetrahedra. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing OMgFe3 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(3), one Fe(6), and one Fe(8) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the second F site, F(2) is bonded in a water-like geometry to one Fe(5) and one Fe(7) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(6), and one Fe(8) atom. In the fourth F site, F(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom. In the fifth F site, F(5) is bonded in an L-shaped geometry to one Fe(6) and one Fe(7) atom. In the sixth F site, F(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom. In the seventh F site, F(7) is bonded in a distorted L-shaped geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the eighth F site, F(8) is bonded in a distorted water-like geometry to one Fe(1) and one Fe(4) atom. is represented by the CIF file [CIF]
data_MgFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.190
_cell_length_b   5.095
_cell_length_c   11.827
_cell_angle_alpha   89.750
_cell_angle_beta   88.249
_cell_angle_gamma   87.420
_symmetry_Int_Tables_number   1
_cell_volume   312.303
_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  0.502  0.014  0.367  1.0
  Fe  Fe1  1  0.932  0.919  0.995  1.0
  Fe  Fe2  1  0.047  0.036  0.236  1.0
  Fe  Fe3  1  0.959  0.917  0.508  1.0
  Fe  Fe4  1  0.097  0.059  0.751  1.0
  Fe  Fe5  1  0.554  0.432  0.120  1.0
  Fe  Fe6  1  0.466  0.547  0.623  1.0
  Fe  Fe7  1  0.454  0.549  0.875  1.0
  Fe  Fe8  1  0.448  0.527  0.372  1.0
  O  O9  1  0.171  0.832  0.377  1.0
  O  O10  1  0.177  0.803  0.628  1.0
  O  O11  1  0.182  0.819  0.873  1.0
  O  O12  1  0.372  0.278  0.249  1.0
  O  O13  1  0.340  0.330  0.749  1.0
  O  O14  1  0.668  0.668  0.996  1.0
  O  O15  1  0.646  0.731  0.494  1.0
  O  O16  1  0.837  0.180  0.110  1.0
  F  F17  1  0.171  0.759  0.111  1.0
  F  F18  1  0.342  0.299  0.996  1.0
  F  F19  1  0.351  0.283  0.507  1.0
  F  F20  1  0.659  0.734  0.247  1.0
  F  F21  1  0.664  0.701  0.745  1.0
  F  F22  1  0.811  0.206  0.391  1.0
  F  F23  1  0.851  0.199  0.625  1.0
  F  F24  1  0.826  0.178  0.866  1.0
[/CIF]
.