The crystal structure described by MgFe6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), two equivalent O(2), two equivalent O(6), and one F(4) atom to form MgO5F octahedra that share corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra, edges with two equivalent Fe(4)O3F3 octahedra, edges with two equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and  a faceface with one Fe(1)O5 trigonal bipyramid. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(2), and two equivalent O(6) atoms to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Fe(6)O3F3 octahedra, corners with four equivalent Mg(1)O5F octahedra, corners with four equivalent Fe(4)O3F3 octahedra,  an edgeedge with one Mg(1)O5F octahedra, edges with two equivalent Fe(1)O5 trigonal bipyramids, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 37-56°. In the second Fe site, Fe(2) is bonded to one O(5), one F(2), two equivalent F(1), and two equivalent F(5) atoms to form FeOF5 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(5)O3F3 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. In the third Fe site, Fe(3) is bonded to one O(4), two equivalent O(1), one F(3), and two equivalent F(6) atoms to form a mixture of corner and edge-sharing FeO3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. In the fourth Fe site, Fe(4) is bonded to one O(6), two equivalent O(3), one F(1), and two equivalent F(2) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(2)OF5 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the fifth Fe site, Fe(5) is bonded to one O(1), two equivalent O(5), one F(5), and two equivalent F(3) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(3)O3F3 octahedra, corners with four equivalent Fe(2)OF5 octahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. In the sixth Fe site, Fe(6) is bonded to one O(2), two equivalent O(4), one F(6), and two equivalent F(4) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Fe(6), and two equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with four equivalent O(6)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(2)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(3)MgFe3 trigonal pyramids. In the third O site, O(3) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form distorted OMgFe3 trigonal pyramids that share corners with two equivalent O(6)Mg2Fe3 trigonal bipyramids, corners with two equivalent O(3)MgFe3 trigonal pyramids, edges with two equivalent O(2)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Fe(4), and two equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with four equivalent O(2)Mg2Fe3 trigonal bipyramids, corners with two equivalent O(3)MgFe3 trigonal pyramids, edges with two equivalent O(2)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(3)MgFe3 trigonal pyramids. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(5) atoms. In the fourth F site, F(4) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Fe(6) atoms. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(2) atoms. In the sixth F site, F(6) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(3) atoms. is represented by the CIF file [CIF]
data_MgFe6(OF)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.045
_cell_length_b   14.562
_cell_length_c   3.073
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   87.265
_symmetry_Int_Tables_number   1
_cell_volume   225.499
_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  0.541  0.994  0.000  1.0
  Fe  Fe1  1  0.047  0.017  0.000  1.0
  Fe  Fe2  1  0.028  0.349  0.000  1.0
  Fe  Fe3  1  0.005  0.659  0.000  1.0
  Fe  Fe4  1  0.520  0.169  0.500  1.0
  Fe  Fe5  1  0.454  0.501  0.500  1.0
  Fe  Fe6  1  0.417  0.815  0.500  1.0
  O  O7  1  0.174  0.603  0.500  1.0
  O  O8  1  0.287  0.947  0.500  1.0
  O  O9  1  0.338  0.117  0.000  1.0
  O  O10  1  0.244  0.766  0.000  1.0
  O  O11  1  0.321  0.440  0.000  1.0
  O  O12  1  0.772  0.051  0.500  1.0
  F  F13  1  0.236  0.274  0.500  1.0
  F  F14  1  0.726  0.232  0.000  1.0
  F  F15  1  0.683  0.568  0.000  1.0
  F  F16  1  0.682  0.868  0.000  1.0
  F  F17  1  0.796  0.406  0.500  1.0
  F  F18  1  0.757  0.721  0.500  1.0
[/CIF]
.
The crystal structure described by MgFe6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), two equivalent O(2), two equivalent O(6), and one F(4) atom to form MgO5F octahedra that share corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra, edges with two equivalent Fe(4)O3F3 octahedra, edges with two equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and  a faceface with one Fe(1)O5 trigonal bipyramid. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(2), and two equivalent O(6) atoms to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Fe(6)O3F3 octahedra, corners with four equivalent Mg(1)O5F octahedra, corners with four equivalent Fe(4)O3F3 octahedra,  an edgeedge with one Mg(1)O5F octahedra, edges with two equivalent Fe(1)O5 trigonal bipyramids, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 37-56°. In the second Fe site, Fe(2) is bonded to one O(5), one F(2), two equivalent F(1), and two equivalent F(5) atoms to form FeOF5 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(5)O3F3 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. In the third Fe site, Fe(3) is bonded to one O(4), two equivalent O(1), one F(3), and two equivalent F(6) atoms to form a mixture of corner and edge-sharing FeO3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. In the fourth Fe site, Fe(4) is bonded to one O(6), two equivalent O(3), one F(1), and two equivalent F(2) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(2)OF5 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the fifth Fe site, Fe(5) is bonded to one O(1), two equivalent O(5), one F(5), and two equivalent F(3) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(3)O3F3 octahedra, corners with four equivalent Fe(2)OF5 octahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. In the sixth Fe site, Fe(6) is bonded to one O(2), two equivalent O(4), one F(6), and two equivalent F(4) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Fe(6), and two equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with four equivalent O(6)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(2)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(3)MgFe3 trigonal pyramids. In the third O site, O(3) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form distorted OMgFe3 trigonal pyramids that share corners with two equivalent O(6)Mg2Fe3 trigonal bipyramids, corners with two equivalent O(3)MgFe3 trigonal pyramids, edges with two equivalent O(2)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Fe(4), and two equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with four equivalent O(2)Mg2Fe3 trigonal bipyramids, corners with two equivalent O(3)MgFe3 trigonal pyramids, edges with two equivalent O(2)Mg2Fe3 trigonal bipyramids, edges with two equivalent O(6)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(3)MgFe3 trigonal pyramids. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(5) atoms. In the fourth F site, F(4) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Fe(6) atoms. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(2) atoms. In the sixth F site, F(6) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(3) atoms. is represented by the CIF file [CIF]
data_MgFe6(OF)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.045
_cell_length_b   14.562
_cell_length_c   3.073
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   87.265
_symmetry_Int_Tables_number   1
_cell_volume   225.499
_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  0.541  0.994  0.000  1.0
  Fe  Fe1  1  0.047  0.017  0.000  1.0
  Fe  Fe2  1  0.028  0.349  0.000  1.0
  Fe  Fe3  1  0.005  0.659  0.000  1.0
  Fe  Fe4  1  0.520  0.169  0.500  1.0
  Fe  Fe5  1  0.454  0.501  0.500  1.0
  Fe  Fe6  1  0.417  0.815  0.500  1.0
  O  O7  1  0.174  0.603  0.500  1.0
  O  O8  1  0.287  0.947  0.500  1.0
  O  O9  1  0.338  0.117  0.000  1.0
  O  O10  1  0.244  0.766  0.000  1.0
  O  O11  1  0.321  0.440  0.000  1.0
  O  O12  1  0.772  0.051  0.500  1.0
  F  F13  1  0.236  0.274  0.500  1.0
  F  F14  1  0.726  0.232  0.000  1.0
  F  F15  1  0.683  0.568  0.000  1.0
  F  F16  1  0.682  0.868  0.000  1.0
  F  F17  1  0.796  0.406  0.500  1.0
  F  F18  1  0.757  0.721  0.500  1.0
[/CIF]
.