The compound described by MgFe12(OF)12 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one F(1), one F(6), two equivalent F(2), and two equivalent F(4) atoms to form MgF6 octahedra that share  a cornercorner with one Fe(5)O3F trigonal pyramid, edges with two equivalent Mg(1)F6 octahedra, edges with two equivalent Fe(3)F6 octahedra, and edges with two equivalent Fe(9)O3F3 octahedra. There are twelve inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(12), two equivalent O(2), and one F(9) atom to form FeO5F octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, and edges with two equivalent Fe(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-55°. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(1), one F(8), and two equivalent F(11) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(5)O3F trigonal pyramids, and edges with two equivalent Fe(2)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. In the third Fe site, Fe(3) is bonded to one F(10), one F(2), two equivalent F(1), and two equivalent F(12) atoms to form distorted FeF6 octahedra that share corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(5)O3F trigonal pyramids, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), one F(5), and two equivalent F(3) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F 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(4), and one F(1) atom to form distorted FeO3F trigonal pyramids that share  a cornercorner with one Mg(1)F6 octahedra, corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, and corners with two equivalent Fe(5)O3F trigonal pyramids. The corner-sharing octahedral tilt angles range from 51-73°. In the sixth Fe site, Fe(6) is bonded in a trigonal planar geometry to one O(2) and two equivalent O(5) atoms. In the seventh Fe site, Fe(7) is bonded to one O(10), two equivalent O(6), one F(3), and two equivalent F(7) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(5)O3F trigonal pyramids, and edges with two equivalent Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the eighth Fe site, Fe(8) is bonded to one O(5), one O(9), two equivalent O(7), and two equivalent F(5) atoms to form FeO4F2 octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, and edges with two equivalent Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. In the ninth Fe site, Fe(9) is bonded to one O(11), two equivalent O(8), one F(4), and two equivalent F(6) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(9)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the tenth Fe site, Fe(10) is bonded to one O(12), two equivalent O(9), one F(7), and two equivalent F(8) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(10)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the eleventh Fe site, Fe(11) is bonded to one O(8), two equivalent O(10), one F(11), and two equivalent F(10) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, and edges with two equivalent Fe(11)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the twelfth Fe site, Fe(12) is bonded to one O(7), two equivalent O(11), one F(12), and two equivalent F(9) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(12)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. There are twelve 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 trigonal non-coplanar geometry to one Fe(6) 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(4) atoms. 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(8) and two equivalent Fe(6) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(5) and two equivalent Fe(7) atoms. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(12) and two equivalent Fe(8) atoms. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(11) and two equivalent Fe(9) atoms. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(8) and two equivalent Fe(10) atoms. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(7) and two equivalent Fe(11) atoms. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Fe(9) and two equivalent Fe(12) atoms. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(10) and two equivalent Fe(1) atoms. There are twelve inequivalent F sites. In the first F site, F(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(5), and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(7) and two equivalent Fe(4) 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(9) atom. In the fifth F site, F(5) is bonded in a 3-coordinate geometry to one Fe(4) and two equivalent Fe(8) atoms. In the sixth F site, F(6) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent Fe(9) atoms. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Fe(10) and two equivalent Fe(7) atoms. In the eighth F site, F(8) is bonded in a distorted T-shaped geometry to one Fe(2) and two equivalent Fe(10) atoms. In the ninth F site, F(9) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(12) atoms. In the tenth F site, F(10) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(11) atoms. In the eleventh F site, F(11) is bonded in a distorted T-shaped geometry to one Fe(11) and two equivalent Fe(2) atoms. In the twelfth F site, F(12) is bonded in a distorted trigonal planar geometry to one Fe(12) and two equivalent Fe(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe12(OF)12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.819
_cell_length_b   14.526
_cell_length_c   3.131
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   87.731
_symmetry_Int_Tables_number   1
_cell_volume   446.214
_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  0.261  0.676  0.500  1.0
  Fe  Fe1  1  1.000  0.014  0.000  1.0
  Fe  Fe2  1  0.997  0.315  0.000  1.0
  Fe  Fe3  1  0.974  0.652  0.000  1.0
  Fe  Fe4  1  0.232  0.161  0.500  1.0
  Fe  Fe5  1  0.208  0.448  0.500  1.0
  Fe  Fe6  1  0.269  0.920  0.500  1.0
  Fe  Fe7  1  0.486  0.342  0.000  1.0
  Fe  Fe8  1  0.530  0.003  0.000  1.0
  Fe  Fe9  1  0.556  0.671  0.000  1.0
  Fe  Fe10  1  0.741  0.151  0.500  1.0
  Fe  Fe11  1  0.717  0.482  0.500  1.0
  Fe  Fe12  1  0.741  0.841  0.500  1.0
  O  O13  1  0.088  0.263  0.500  1.0
  O  O14  1  0.079  0.943  0.500  1.0
  O  O15  1  0.162  0.101  0.000  1.0
  O  O16  1  0.113  0.423  0.000  1.0
  O  O17  1  0.378  0.919  0.000  1.0
  O  O18  1  0.391  0.398  0.500  1.0
  O  O19  1  0.618  0.946  0.500  1.0
  O  O20  1  0.615  0.600  0.500  1.0
  O  O21  1  0.646  0.111  0.000  1.0
  O  O22  1  0.640  0.427  0.000  1.0
  O  O23  1  0.672  0.772  0.000  1.0
  O  O24  1  0.901  0.074  0.500  1.0
  F  F25  1  0.110  0.586  0.500  1.0
  F  F26  1  0.156  0.729  0.000  1.0
  F  F27  1  0.341  0.237  0.000  1.0
  F  F28  1  0.350  0.605  0.000  1.0
  F  F29  1  0.413  0.081  0.500  1.0
  F  F30  1  0.434  0.736  0.500  1.0
  F  F31  1  0.583  0.270  0.500  1.0
  F  F32  1  0.830  0.238  0.000  1.0
  F  F33  1  0.851  0.896  0.000  1.0
  F  F34  1  0.845  0.547  0.000  1.0
  F  F35  1  0.883  0.389  0.500  1.0
  F  F36  1  0.903  0.731  0.500  1.0
[/CIF]
.
The compound described by MgFe12(OF)12 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one F(1), one F(6), two equivalent F(2), and two equivalent F(4) atoms to form MgF6 octahedra that share  a cornercorner with one Fe(5)O3F trigonal pyramid, edges with two equivalent Mg(1)F6 octahedra, edges with two equivalent Fe(3)F6 octahedra, and edges with two equivalent Fe(9)O3F3 octahedra. There are twelve inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(12), two equivalent O(2), and one F(9) atom to form FeO5F octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, and edges with two equivalent Fe(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-55°. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(1), one F(8), and two equivalent F(11) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(5)O3F trigonal pyramids, and edges with two equivalent Fe(2)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. In the third Fe site, Fe(3) is bonded to one F(10), one F(2), two equivalent F(1), and two equivalent F(12) atoms to form distorted FeF6 octahedra that share corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(5)O3F trigonal pyramids, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), one F(5), and two equivalent F(3) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F 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(4), and one F(1) atom to form distorted FeO3F trigonal pyramids that share  a cornercorner with one Mg(1)F6 octahedra, corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, and corners with two equivalent Fe(5)O3F trigonal pyramids. The corner-sharing octahedral tilt angles range from 51-73°. In the sixth Fe site, Fe(6) is bonded in a trigonal planar geometry to one O(2) and two equivalent O(5) atoms. In the seventh Fe site, Fe(7) is bonded to one O(10), two equivalent O(6), one F(3), and two equivalent F(7) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(5)O3F trigonal pyramids, and edges with two equivalent Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the eighth Fe site, Fe(8) is bonded to one O(5), one O(9), two equivalent O(7), and two equivalent F(5) atoms to form FeO4F2 octahedra that share corners with two equivalent Fe(10)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, and edges with two equivalent Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. In the ninth Fe site, Fe(9) is bonded to one O(11), two equivalent O(8), one F(4), and two equivalent F(6) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(9)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the tenth Fe site, Fe(10) is bonded to one O(12), two equivalent O(9), one F(7), and two equivalent F(8) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(10)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the eleventh Fe site, Fe(11) is bonded to one O(8), two equivalent O(10), one F(11), and two equivalent F(10) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, and edges with two equivalent Fe(11)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the twelfth Fe site, Fe(12) is bonded to one O(7), two equivalent O(11), one F(12), and two equivalent F(9) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(12)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. There are twelve 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 trigonal non-coplanar geometry to one Fe(6) 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(4) atoms. 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(8) and two equivalent Fe(6) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(5) and two equivalent Fe(7) atoms. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(12) and two equivalent Fe(8) atoms. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(11) and two equivalent Fe(9) atoms. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(8) and two equivalent Fe(10) atoms. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(7) and two equivalent Fe(11) atoms. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Fe(9) and two equivalent Fe(12) atoms. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(10) and two equivalent Fe(1) atoms. There are twelve inequivalent F sites. In the first F site, F(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(5), and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(7) and two equivalent Fe(4) 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(9) atom. In the fifth F site, F(5) is bonded in a 3-coordinate geometry to one Fe(4) and two equivalent Fe(8) atoms. In the sixth F site, F(6) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent Fe(9) atoms. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Fe(10) and two equivalent Fe(7) atoms. In the eighth F site, F(8) is bonded in a distorted T-shaped geometry to one Fe(2) and two equivalent Fe(10) atoms. In the ninth F site, F(9) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(12) atoms. In the tenth F site, F(10) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(11) atoms. In the eleventh F site, F(11) is bonded in a distorted T-shaped geometry to one Fe(11) and two equivalent Fe(2) atoms. In the twelfth F site, F(12) is bonded in a distorted trigonal planar geometry to one Fe(12) and two equivalent Fe(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe12(OF)12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.819
_cell_length_b   14.526
_cell_length_c   3.131
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   87.731
_symmetry_Int_Tables_number   1
_cell_volume   446.214
_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  0.261  0.676  0.500  1.0
  Fe  Fe1  1  1.000  0.014  0.000  1.0
  Fe  Fe2  1  0.997  0.315  0.000  1.0
  Fe  Fe3  1  0.974  0.652  0.000  1.0
  Fe  Fe4  1  0.232  0.161  0.500  1.0
  Fe  Fe5  1  0.208  0.448  0.500  1.0
  Fe  Fe6  1  0.269  0.920  0.500  1.0
  Fe  Fe7  1  0.486  0.342  0.000  1.0
  Fe  Fe8  1  0.530  0.003  0.000  1.0
  Fe  Fe9  1  0.556  0.671  0.000  1.0
  Fe  Fe10  1  0.741  0.151  0.500  1.0
  Fe  Fe11  1  0.717  0.482  0.500  1.0
  Fe  Fe12  1  0.741  0.841  0.500  1.0
  O  O13  1  0.088  0.263  0.500  1.0
  O  O14  1  0.079  0.943  0.500  1.0
  O  O15  1  0.162  0.101  0.000  1.0
  O  O16  1  0.113  0.423  0.000  1.0
  O  O17  1  0.378  0.919  0.000  1.0
  O  O18  1  0.391  0.398  0.500  1.0
  O  O19  1  0.618  0.946  0.500  1.0
  O  O20  1  0.615  0.600  0.500  1.0
  O  O21  1  0.646  0.111  0.000  1.0
  O  O22  1  0.640  0.427  0.000  1.0
  O  O23  1  0.672  0.772  0.000  1.0
  O  O24  1  0.901  0.074  0.500  1.0
  F  F25  1  0.110  0.586  0.500  1.0
  F  F26  1  0.156  0.729  0.000  1.0
  F  F27  1  0.341  0.237  0.000  1.0
  F  F28  1  0.350  0.605  0.000  1.0
  F  F29  1  0.413  0.081  0.500  1.0
  F  F30  1  0.434  0.736  0.500  1.0
  F  F31  1  0.583  0.270  0.500  1.0
  F  F32  1  0.830  0.238  0.000  1.0
  F  F33  1  0.851  0.896  0.000  1.0
  F  F34  1  0.845  0.547  0.000  1.0
  F  F35  1  0.883  0.389  0.500  1.0
  F  F36  1  0.903  0.731  0.500  1.0
[/CIF]
.