The material described by MgFe8(OF)8 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(6), one F(2), two equivalent F(4), and two equivalent F(5) atoms to form MgOF5 octahedra that share corners with two equivalent Fe(6)F6 octahedra, edges with two equivalent Mg(1)OF5 octahedra, and  a faceface with one Fe(6)F6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(2), one F(7), and two equivalent F(8) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(4)O4 trigonal pyramids, and edges with two equivalent Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Fe site, Fe(2) is bonded to one O(4), one O(7), two equivalent O(1), and two equivalent O(8) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(4)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 54°. In the third Fe site, Fe(3) is bonded to one O(1), two equivalent O(3), one F(3), and two equivalent F(1) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 50-54°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(8), and two equivalent O(4) atoms to form FeO4 trigonal pyramids that share corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(4)O4 trigonal pyramids, and edges with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the fifth Fe site, Fe(5) is bonded in a 6-coordinate geometry to one O(6), two equivalent O(5), one F(1), and two equivalent F(4) atoms. In the sixth Fe site, Fe(6) is bonded to one F(2), one F(6), two equivalent F(3), and two equivalent F(5) atoms to form distorted FeF6 octahedra that share corners with two equivalent Mg(1)OF5 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, edges with two equivalent Fe(6)F6 octahedra, and  a faceface with one Mg(1)OF5 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the seventh Fe site, Fe(7) is bonded to one O(5), two equivalent O(7), one F(8), and two equivalent F(6) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the eighth Fe site, Fe(8) is bonded in a 5-coordinate geometry to one O(8), two equivalent O(6), and two equivalent F(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(7) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(5), and two equivalent Fe(8) atoms to form corner-sharing OMgFe3 tetrahedra. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(7) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Fe(4), one Fe(8), and two equivalent Fe(2) atoms. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in an L-shaped geometry to one Mg(1) and one Fe(6) atom. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted water-like geometry to two equivalent Mg(1) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a 4-coordinate geometry to two equivalent Mg(1) and two equivalent Fe(6) atoms. In the sixth F site, F(6) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(7) atoms. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(8) atoms. In the eighth F site, F(8) is bonded in a distorted trigonal planar geometry to one Fe(7) and two equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_MgFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.788
_cell_length_b   9.821
_cell_length_c   3.142
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   94.933
_symmetry_Int_Tables_number   1
_cell_volume   300.875
_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  0.479  0.737  0.000  1.0
  Fe  Fe1  1  0.009  0.014  0.000  1.0
  Fe  Fe2  1  0.019  0.476  0.000  1.0
  Fe  Fe3  1  0.226  0.258  0.500  1.0
  Fe  Fe4  1  0.117  0.732  0.500  1.0
  Fe  Fe5  1  0.545  0.458  0.000  1.0
  Fe  Fe6  1  0.481  0.033  0.000  1.0
  Fe  Fe7  1  0.766  0.269  0.500  1.0
  Fe  Fe8  1  0.775  0.710  0.500  1.0
  O  O9  1  0.107  0.402  0.500  1.0
  O  O10  1  0.071  0.915  0.500  1.0
  O  O11  1  0.147  0.160  0.000  1.0
  O  O12  1  0.164  0.644  0.000  1.0
  O  O13  1  0.611  0.365  0.500  1.0
  O  O14  1  0.665  0.647  0.000  1.0
  O  O15  1  0.861  0.347  0.000  1.0
  O  O16  1  0.937  0.616  0.500  1.0
  F  F17  1  0.346  0.353  0.000  1.0
  F  F18  1  0.345  0.871  0.000  1.0
  F  F19  1  0.389  0.129  0.500  1.0
  F  F20  1  0.433  0.618  0.500  1.0
  F  F21  1  0.564  0.872  0.500  1.0
  F  F22  1  0.666  0.133  0.000  1.0
  F  F23  1  0.841  0.850  0.000  1.0
  F  F24  1  0.896  0.098  0.500  1.0
[/CIF]
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The material described by MgFe8(OF)8 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(6), one F(2), two equivalent F(4), and two equivalent F(5) atoms to form MgOF5 octahedra that share corners with two equivalent Fe(6)F6 octahedra, edges with two equivalent Mg(1)OF5 octahedra, and  a faceface with one Fe(6)F6 octahedra. The corner-sharing octahedral tilt angles are 42°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(2), one F(7), and two equivalent F(8) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(4)O4 trigonal pyramids, and edges with two equivalent Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Fe site, Fe(2) is bonded to one O(4), one O(7), two equivalent O(1), and two equivalent O(8) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(4)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 54°. In the third Fe site, Fe(3) is bonded to one O(1), two equivalent O(3), one F(3), and two equivalent F(1) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 50-54°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(8), and two equivalent O(4) atoms to form FeO4 trigonal pyramids that share corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(4)O4 trigonal pyramids, and edges with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the fifth Fe site, Fe(5) is bonded in a 6-coordinate geometry to one O(6), two equivalent O(5), one F(1), and two equivalent F(4) atoms. In the sixth Fe site, Fe(6) is bonded to one F(2), one F(6), two equivalent F(3), and two equivalent F(5) atoms to form distorted FeF6 octahedra that share corners with two equivalent Mg(1)OF5 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, edges with two equivalent Fe(6)F6 octahedra, and  a faceface with one Mg(1)OF5 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the seventh Fe site, Fe(7) is bonded to one O(5), two equivalent O(7), one F(8), and two equivalent F(6) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the eighth Fe site, Fe(8) is bonded in a 5-coordinate geometry to one O(8), two equivalent O(6), and two equivalent F(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(7) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(5), and two equivalent Fe(8) atoms to form corner-sharing OMgFe3 tetrahedra. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(7) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Fe(4), one Fe(8), and two equivalent Fe(2) atoms. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in an L-shaped geometry to one Mg(1) and one Fe(6) atom. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted water-like geometry to two equivalent Mg(1) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a 4-coordinate geometry to two equivalent Mg(1) and two equivalent Fe(6) atoms. In the sixth F site, F(6) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(7) atoms. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(8) atoms. In the eighth F site, F(8) is bonded in a distorted trigonal planar geometry to one Fe(7) and two equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_MgFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.788
_cell_length_b   9.821
_cell_length_c   3.142
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   94.933
_symmetry_Int_Tables_number   1
_cell_volume   300.875
_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  0.479  0.737  0.000  1.0
  Fe  Fe1  1  0.009  0.014  0.000  1.0
  Fe  Fe2  1  0.019  0.476  0.000  1.0
  Fe  Fe3  1  0.226  0.258  0.500  1.0
  Fe  Fe4  1  0.117  0.732  0.500  1.0
  Fe  Fe5  1  0.545  0.458  0.000  1.0
  Fe  Fe6  1  0.481  0.033  0.000  1.0
  Fe  Fe7  1  0.766  0.269  0.500  1.0
  Fe  Fe8  1  0.775  0.710  0.500  1.0
  O  O9  1  0.107  0.402  0.500  1.0
  O  O10  1  0.071  0.915  0.500  1.0
  O  O11  1  0.147  0.160  0.000  1.0
  O  O12  1  0.164  0.644  0.000  1.0
  O  O13  1  0.611  0.365  0.500  1.0
  O  O14  1  0.665  0.647  0.000  1.0
  O  O15  1  0.861  0.347  0.000  1.0
  O  O16  1  0.937  0.616  0.500  1.0
  F  F17  1  0.346  0.353  0.000  1.0
  F  F18  1  0.345  0.871  0.000  1.0
  F  F19  1  0.389  0.129  0.500  1.0
  F  F20  1  0.433  0.618  0.500  1.0
  F  F21  1  0.564  0.872  0.500  1.0
  F  F22  1  0.666  0.133  0.000  1.0
  F  F23  1  0.841  0.850  0.000  1.0
  F  F24  1  0.896  0.098  0.500  1.0
[/CIF]
.