The crystal structure described by MgFe6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to two equivalent O(3), one F(1), one F(5), and two equivalent F(4) atoms to form MgO2F4 octahedra that share corners with two equivalent Fe(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra, edges with two equivalent Fe(1)O3F3 octahedra, edges with two equivalent Fe(2)O3F3 octahedra, and  an edgeedge with one Fe(4)O3F2 trigonal bipyramid. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(6), one F(3), and two equivalent F(1) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra, and edges with two equivalent Fe(1)O3F3 octahedra. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(1), one F(4), and two equivalent F(5) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra, and edges with two equivalent Fe(2)O3F3 octahedra. In the third Fe site, Fe(3) is bonded to one O(5), two equivalent O(2), one F(2), and two equivalent F(6) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids, and edges with two equivalent Fe(3)O3F3 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), and two equivalent F(2) atoms to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O2F4 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra,  an edgeedge with one Mg(1)O2F4 octahedra, and edges with two equivalent Fe(4)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 32-65°. In the fifth Fe site, Fe(5) is bonded to one O(2), two equivalent O(4), and two equivalent F(3) atoms to form distorted FeO3F2 square pyramids that share corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, and edges with two equivalent Fe(5)O3F2 square pyramids. The corner-sharing octahedral tilt angles range from 46-54°. In the sixth Fe site, Fe(6) is bonded in a trigonal planar geometry to one O(6) and two equivalent O(5) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form distorted edge-sharing OMg2Fe3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(5) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(2) atom. In the fifth F site, F(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1) and two equivalent Fe(2) atoms. In the sixth F site, F(6) is bonded in a water-like geometry to two equivalent Fe(3) atoms. is represented by the CIF card [CIF]
data_MgFe6(OF)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.475
_cell_length_b   15.175
_cell_length_c   3.087
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   137.373
_symmetry_Int_Tables_number   1
_cell_volume   237.155
_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  0.517  0.167  0.500  1.0
  Fe  Fe1  1  0.997  0.015  0.000  1.0
  Fe  Fe2  1  0.091  0.367  0.000  1.0
  Fe  Fe3  1  0.009  0.666  0.000  1.0
  Fe  Fe4  1  0.442  0.326  0.500  1.0
  Fe  Fe5  1  0.427  0.659  0.500  1.0
  Fe  Fe6  1  0.485  0.932  0.500  1.0
  O  O7  1  0.190  0.336  0.500  1.0
  O  O8  1  0.183  0.664  0.500  1.0
  O  O9  1  0.365  0.195  0.000  1.0
  O  O10  1  0.329  0.553  0.000  1.0
  O  O11  1  0.263  0.852  0.000  1.0
  O  O12  1  0.850  0.020  0.500  1.0
  F  F13  1  0.151  0.988  0.500  1.0
  F  F14  1  0.697  0.462  0.000  1.0
  F  F15  1  0.679  0.804  0.000  1.0
  F  F16  1  0.680  0.159  0.000  1.0
  F  F17  1  0.867  0.353  0.500  1.0
  F  F18  1  0.805  0.647  0.500  1.0
[/CIF]
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The crystal structure described by MgFe6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to two equivalent O(3), one F(1), one F(5), and two equivalent F(4) atoms to form MgO2F4 octahedra that share corners with two equivalent Fe(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra, edges with two equivalent Fe(1)O3F3 octahedra, edges with two equivalent Fe(2)O3F3 octahedra, and  an edgeedge with one Fe(4)O3F2 trigonal bipyramid. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(6), one F(3), and two equivalent F(1) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra, and edges with two equivalent Fe(1)O3F3 octahedra. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(1), one F(4), and two equivalent F(5) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra, and edges with two equivalent Fe(2)O3F3 octahedra. In the third Fe site, Fe(3) is bonded to one O(5), two equivalent O(2), one F(2), and two equivalent F(6) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids, and edges with two equivalent Fe(3)O3F3 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), and two equivalent F(2) atoms to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O2F4 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra,  an edgeedge with one Mg(1)O2F4 octahedra, and edges with two equivalent Fe(4)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 32-65°. In the fifth Fe site, Fe(5) is bonded to one O(2), two equivalent O(4), and two equivalent F(3) atoms to form distorted FeO3F2 square pyramids that share corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, and edges with two equivalent Fe(5)O3F2 square pyramids. The corner-sharing octahedral tilt angles range from 46-54°. In the sixth Fe site, Fe(6) is bonded in a trigonal planar geometry to one O(6) and two equivalent O(5) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form distorted edge-sharing OMg2Fe3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(5) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(2) atom. In the fifth F site, F(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1) and two equivalent Fe(2) atoms. In the sixth F site, F(6) is bonded in a water-like geometry to two equivalent Fe(3) atoms. is represented by the CIF card [CIF]
data_MgFe6(OF)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.475
_cell_length_b   15.175
_cell_length_c   3.087
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   137.373
_symmetry_Int_Tables_number   1
_cell_volume   237.155
_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  0.517  0.167  0.500  1.0
  Fe  Fe1  1  0.997  0.015  0.000  1.0
  Fe  Fe2  1  0.091  0.367  0.000  1.0
  Fe  Fe3  1  0.009  0.666  0.000  1.0
  Fe  Fe4  1  0.442  0.326  0.500  1.0
  Fe  Fe5  1  0.427  0.659  0.500  1.0
  Fe  Fe6  1  0.485  0.932  0.500  1.0
  O  O7  1  0.190  0.336  0.500  1.0
  O  O8  1  0.183  0.664  0.500  1.0
  O  O9  1  0.365  0.195  0.000  1.0
  O  O10  1  0.329  0.553  0.000  1.0
  O  O11  1  0.263  0.852  0.000  1.0
  O  O12  1  0.850  0.020  0.500  1.0
  F  F13  1  0.151  0.988  0.500  1.0
  F  F14  1  0.697  0.462  0.000  1.0
  F  F15  1  0.679  0.804  0.000  1.0
  F  F16  1  0.680  0.159  0.000  1.0
  F  F17  1  0.867  0.353  0.500  1.0
  F  F18  1  0.805  0.647  0.500  1.0
[/CIF]
.