The compound described by MgFe8(OF)8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Fe(7)O3F3 octahedra, edges with two equivalent Fe(8)O3F3 octahedra,  a faceface with one Fe(5)O3F3 octahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. 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 a mixture of edge and corner-sharing FeO3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. 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 Mg(1)O6 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O3F3 octahedra, edges with two equivalent Fe(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-55°. 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(5)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 47-53°. In the fourth Fe site, Fe(4) is bonded to one O(2), two equivalent O(4), one F(4), and two equivalent F(2) 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(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the fifth Fe site, Fe(5) is bonded to one O(6), two equivalent O(5), one F(1), and two equivalent F(4) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O3F3 octahedra, edges with two equivalent Fe(5)O3F3 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. 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 FeF6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O3F3 octahedra, and edges with two equivalent Fe(6)F6 octahedra. The corner-sharing octahedral tilt angles range from 45-49°. 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 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(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the eighth Fe site, Fe(8) is bonded to one O(8), two equivalent O(6), one F(5), and two equivalent F(7) 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(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Fe(8)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 44-54°. 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 planar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the fifth O site, O(5) is bonded to two equivalent Mg(1), one Fe(7), and two equivalent Fe(5) atoms to form distorted OMg2Fe3 square pyramids that share edges with two equivalent O(5)Mg2Fe3 square pyramids, edges with two equivalent O(6)MgFe3 trigonal pyramids, and edges with two equivalent O(7)MgFe3 trigonal pyramids. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(5), and two equivalent Fe(8) atoms to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(7)MgFe3 trigonal pyramid, corners with two equivalent O(6)MgFe3 trigonal pyramids, and edges with two equivalent O(5)Mg2Fe3 square pyramids. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(7) atoms to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(6)MgFe3 trigonal pyramid, corners with two equivalent O(7)MgFe3 trigonal pyramids, and edges with two equivalent O(5)Mg2Fe3 square pyramids. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to two equivalent Mg(1), 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 T-shaped geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(4) atoms. 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 T-shaped geometry to one Fe(4) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(8) 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 T-shaped geometry to one Fe(1) and two equivalent Fe(8) atoms. In the eighth F site, F(8) is bonded in a distorted T-shaped 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   9.608
_cell_length_b   9.793
_cell_length_c   3.083
_cell_angle_alpha   89.714
_cell_angle_beta   90.251
_cell_angle_gamma   90.091
_symmetry_Int_Tables_number   1
_cell_volume   290.102
_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  0.753  0.498  0.035  1.0
  Fe  Fe1  1  0.025  0.998  0.001  1.0
  Fe  Fe2  1  0.029  0.497  0.982  1.0
  Fe  Fe3  1  0.225  0.246  0.497  1.0
  Fe  Fe4  1  0.223  0.747  0.495  1.0
  Fe  Fe5  1  0.489  0.502  0.003  1.0
  Fe  Fe6  1  0.493  0.000  0.007  1.0
  Fe  Fe7  1  0.760  0.254  0.524  1.0
  Fe  Fe8  1  0.748  0.747  0.525  1.0
  O  O9  1  0.113  0.408  0.488  1.0
  O  O10  1  0.101  0.905  0.502  1.0
  O  O11  1  0.146  0.153  0.998  1.0
  O  O12  1  0.145  0.657  0.996  1.0
  O  O13  1  0.628  0.413  0.521  1.0
  O  O14  1  0.647  0.670  0.023  1.0
  O  O15  1  0.861  0.328  0.021  1.0
  O  O16  1  0.880  0.582  0.533  1.0
  F  F17  1  0.350  0.338  0.997  1.0
  F  F18  1  0.347  0.846  0.998  1.0
  F  F19  1  0.393  0.107  0.503  1.0
  F  F20  1  0.386  0.609  0.498  1.0
  F  F21  1  0.610  0.910  0.512  1.0
  F  F22  1  0.652  0.149  0.019  1.0
  F  F23  1  0.852  0.852  0.018  1.0
  F  F24  1  0.896  0.083  0.512  1.0
[/CIF]
.
The compound described by MgFe8(OF)8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Fe(7)O3F3 octahedra, edges with two equivalent Fe(8)O3F3 octahedra,  a faceface with one Fe(5)O3F3 octahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. 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 a mixture of edge and corner-sharing FeO3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. 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 Mg(1)O6 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O3F3 octahedra, edges with two equivalent Fe(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-55°. 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(5)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 47-53°. In the fourth Fe site, Fe(4) is bonded to one O(2), two equivalent O(4), one F(4), and two equivalent F(2) 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(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the fifth Fe site, Fe(5) is bonded to one O(6), two equivalent O(5), one F(1), and two equivalent F(4) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O3F3 octahedra, edges with two equivalent Fe(5)O3F3 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. 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 FeF6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O3F3 octahedra, and edges with two equivalent Fe(6)F6 octahedra. The corner-sharing octahedral tilt angles range from 45-49°. 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 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(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the eighth Fe site, Fe(8) is bonded to one O(8), two equivalent O(6), one F(5), and two equivalent F(7) 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(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Fe(8)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 44-54°. 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 planar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the fifth O site, O(5) is bonded to two equivalent Mg(1), one Fe(7), and two equivalent Fe(5) atoms to form distorted OMg2Fe3 square pyramids that share edges with two equivalent O(5)Mg2Fe3 square pyramids, edges with two equivalent O(6)MgFe3 trigonal pyramids, and edges with two equivalent O(7)MgFe3 trigonal pyramids. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(5), and two equivalent Fe(8) atoms to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(7)MgFe3 trigonal pyramid, corners with two equivalent O(6)MgFe3 trigonal pyramids, and edges with two equivalent O(5)Mg2Fe3 square pyramids. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(7) atoms to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(6)MgFe3 trigonal pyramid, corners with two equivalent O(7)MgFe3 trigonal pyramids, and edges with two equivalent O(5)Mg2Fe3 square pyramids. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to two equivalent Mg(1), 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 T-shaped geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(4) atoms. 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 T-shaped geometry to one Fe(4) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(8) 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 T-shaped geometry to one Fe(1) and two equivalent Fe(8) atoms. In the eighth F site, F(8) is bonded in a distorted T-shaped 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   9.608
_cell_length_b   9.793
_cell_length_c   3.083
_cell_angle_alpha   89.714
_cell_angle_beta   90.251
_cell_angle_gamma   90.091
_symmetry_Int_Tables_number   1
_cell_volume   290.102
_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  0.753  0.498  0.035  1.0
  Fe  Fe1  1  0.025  0.998  0.001  1.0
  Fe  Fe2  1  0.029  0.497  0.982  1.0
  Fe  Fe3  1  0.225  0.246  0.497  1.0
  Fe  Fe4  1  0.223  0.747  0.495  1.0
  Fe  Fe5  1  0.489  0.502  0.003  1.0
  Fe  Fe6  1  0.493  0.000  0.007  1.0
  Fe  Fe7  1  0.760  0.254  0.524  1.0
  Fe  Fe8  1  0.748  0.747  0.525  1.0
  O  O9  1  0.113  0.408  0.488  1.0
  O  O10  1  0.101  0.905  0.502  1.0
  O  O11  1  0.146  0.153  0.998  1.0
  O  O12  1  0.145  0.657  0.996  1.0
  O  O13  1  0.628  0.413  0.521  1.0
  O  O14  1  0.647  0.670  0.023  1.0
  O  O15  1  0.861  0.328  0.021  1.0
  O  O16  1  0.880  0.582  0.533  1.0
  F  F17  1  0.350  0.338  0.997  1.0
  F  F18  1  0.347  0.846  0.998  1.0
  F  F19  1  0.393  0.107  0.503  1.0
  F  F20  1  0.386  0.609  0.498  1.0
  F  F21  1  0.610  0.910  0.512  1.0
  F  F22  1  0.652  0.149  0.019  1.0
  F  F23  1  0.852  0.852  0.018  1.0
  F  F24  1  0.896  0.083  0.512  1.0
[/CIF]
.