The material described by MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(13), one O(4), one O(6), and one O(7) atom. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(3), one O(5), and one F(2) atom. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(12), one O(13), and one O(4) atom. In the third Fe site, Fe(3) is bonded to one O(13), one O(14), one O(2), one O(4), one O(7), and one F(1) atom to form FeO5F octahedra that share corners with three equivalent Fe(8)O4F trigonal bipyramids, corners with three equivalent Fe(6)O5 trigonal bipyramids, and  an edgeedge with one Fe(4)O4F square pyramid. In the fourth Fe site, Fe(4) is bonded to one O(14), one O(2), one O(3), one O(8), and one F(2) atom to form distorted FeO4F square pyramids that share corners with three equivalent Fe(7)O5F octahedra, corners with three equivalent Fe(6)O5 trigonal bipyramids, and  an edgeedge with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 41-52°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(10), one O(12), one O(5), one O(6), and one O(9) atom to form FeO6 octahedra that share  an edgeedge with one Fe(7)O5F octahedra and  an edgeedge with one Fe(8)O4F trigonal bipyramid. In the sixth Fe site, Fe(6) is bonded to one O(11), one O(14), one O(2), one O(7), and one O(8) atom to form FeO5 trigonal bipyramids that share corners with three equivalent Fe(3)O5F octahedra, corners with three equivalent Fe(4)O4F square pyramids, and  an edgeedge with one Fe(7)O5F octahedra. The corner-sharing octahedral tilt angles range from 41-45°. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(3), one O(5), one O(8), one O(9), and one F(2) atom to form FeO5F octahedra that share corners with three equivalent Fe(4)O4F square pyramids,  an edgeedge with one Fe(5)O6 octahedra, and  an edgeedge with one Fe(6)O5 trigonal bipyramid. In the eighth Fe site, Fe(8) is bonded to one O(10), one O(13), one O(4), one O(6), and one F(1) atom to form FeO4F trigonal bipyramids that share corners with three equivalent Fe(3)O5F octahedra and  an edgeedge with one Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-45°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted face and corner-sharing OMgFe3 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a T-shaped geometry to one Mg(1), one Fe(5), and one Fe(8) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(3), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Fe(5) and one Fe(7) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(5), and one Fe(8) atom. In the eleventh O site, O(11) is bonded in a water-like geometry to one Fe(6) and one Fe(7) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the thirteenth O site, O(13) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted face and corner-sharing OMgFe3 trigonal pyramids. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to one Fe(3) and one Fe(8) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(7) atom. is represented by the CIF file [CIF]
data_MgFe8(O7F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.154
_cell_length_b   5.153
_cell_length_c   12.088
_cell_angle_alpha   93.484
_cell_angle_beta   93.039
_cell_angle_gamma   75.948
_symmetry_Int_Tables_number   1
_cell_volume   310.593
_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  0.243  0.234  0.366  1.0
  Fe  Fe1  1  0.082  0.060  0.008  1.0
  Fe  Fe2  1  0.940  0.944  0.238  1.0
  Fe  Fe3  1  0.004  0.003  0.508  1.0
  Fe  Fe4  1  0.048  0.033  0.749  1.0
  Fe  Fe5  1  0.503  0.495  0.120  1.0
  Fe  Fe6  1  0.426  0.423  0.643  1.0
  Fe  Fe7  1  0.429  0.473  0.882  1.0
  Fe  Fe8  1  0.586  0.584  0.354  1.0
  O  O9  1  0.207  0.815  0.125  1.0
  O  O10  1  0.196  0.783  0.626  1.0
  O  O11  1  0.168  0.814  0.876  1.0
  O  O12  1  0.231  0.841  0.373  1.0
  O  O13  1  0.299  0.311  0.998  1.0
  O  O14  1  0.391  0.379  0.250  1.0
  O  O15  1  0.273  0.265  0.526  1.0
  O  O16  1  0.269  0.286  0.766  1.0
  O  O17  1  0.616  0.620  0.994  1.0
  O  O18  1  0.715  0.710  0.231  1.0
  O  O19  1  0.585  0.587  0.762  1.0
  O  O20  1  0.820  0.199  0.121  1.0
  O  O21  1  0.846  0.230  0.373  1.0
  O  O22  1  0.788  0.194  0.630  1.0
  F  F23  1  0.755  0.756  0.476  1.0
  F  F24  1  0.790  0.168  0.877  1.0
[/CIF]
.
The material described by MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(13), one O(4), one O(6), and one O(7) atom. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(3), one O(5), and one F(2) atom. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(12), one O(13), and one O(4) atom. In the third Fe site, Fe(3) is bonded to one O(13), one O(14), one O(2), one O(4), one O(7), and one F(1) atom to form FeO5F octahedra that share corners with three equivalent Fe(8)O4F trigonal bipyramids, corners with three equivalent Fe(6)O5 trigonal bipyramids, and  an edgeedge with one Fe(4)O4F square pyramid. In the fourth Fe site, Fe(4) is bonded to one O(14), one O(2), one O(3), one O(8), and one F(2) atom to form distorted FeO4F square pyramids that share corners with three equivalent Fe(7)O5F octahedra, corners with three equivalent Fe(6)O5 trigonal bipyramids, and  an edgeedge with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 41-52°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(10), one O(12), one O(5), one O(6), and one O(9) atom to form FeO6 octahedra that share  an edgeedge with one Fe(7)O5F octahedra and  an edgeedge with one Fe(8)O4F trigonal bipyramid. In the sixth Fe site, Fe(6) is bonded to one O(11), one O(14), one O(2), one O(7), and one O(8) atom to form FeO5 trigonal bipyramids that share corners with three equivalent Fe(3)O5F octahedra, corners with three equivalent Fe(4)O4F square pyramids, and  an edgeedge with one Fe(7)O5F octahedra. The corner-sharing octahedral tilt angles range from 41-45°. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(3), one O(5), one O(8), one O(9), and one F(2) atom to form FeO5F octahedra that share corners with three equivalent Fe(4)O4F square pyramids,  an edgeedge with one Fe(5)O6 octahedra, and  an edgeedge with one Fe(6)O5 trigonal bipyramid. In the eighth Fe site, Fe(8) is bonded to one O(10), one O(13), one O(4), one O(6), and one F(1) atom to form FeO4F trigonal bipyramids that share corners with three equivalent Fe(3)O5F octahedra and  an edgeedge with one Fe(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-45°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted face and corner-sharing OMgFe3 trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a T-shaped geometry to one Mg(1), one Fe(5), and one Fe(8) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(3), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Fe(5) and one Fe(7) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(5), and one Fe(8) atom. In the eleventh O site, O(11) is bonded in a water-like geometry to one Fe(6) and one Fe(7) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the thirteenth O site, O(13) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted face and corner-sharing OMgFe3 trigonal pyramids. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to one Fe(3) and one Fe(8) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(7) atom. is represented by the CIF file [CIF]
data_MgFe8(O7F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.154
_cell_length_b   5.153
_cell_length_c   12.088
_cell_angle_alpha   93.484
_cell_angle_beta   93.039
_cell_angle_gamma   75.948
_symmetry_Int_Tables_number   1
_cell_volume   310.593
_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  0.243  0.234  0.366  1.0
  Fe  Fe1  1  0.082  0.060  0.008  1.0
  Fe  Fe2  1  0.940  0.944  0.238  1.0
  Fe  Fe3  1  0.004  0.003  0.508  1.0
  Fe  Fe4  1  0.048  0.033  0.749  1.0
  Fe  Fe5  1  0.503  0.495  0.120  1.0
  Fe  Fe6  1  0.426  0.423  0.643  1.0
  Fe  Fe7  1  0.429  0.473  0.882  1.0
  Fe  Fe8  1  0.586  0.584  0.354  1.0
  O  O9  1  0.207  0.815  0.125  1.0
  O  O10  1  0.196  0.783  0.626  1.0
  O  O11  1  0.168  0.814  0.876  1.0
  O  O12  1  0.231  0.841  0.373  1.0
  O  O13  1  0.299  0.311  0.998  1.0
  O  O14  1  0.391  0.379  0.250  1.0
  O  O15  1  0.273  0.265  0.526  1.0
  O  O16  1  0.269  0.286  0.766  1.0
  O  O17  1  0.616  0.620  0.994  1.0
  O  O18  1  0.715  0.710  0.231  1.0
  O  O19  1  0.585  0.587  0.762  1.0
  O  O20  1  0.820  0.199  0.121  1.0
  O  O21  1  0.846  0.230  0.373  1.0
  O  O22  1  0.788  0.194  0.630  1.0
  F  F23  1  0.755  0.756  0.476  1.0
  F  F24  1  0.790  0.168  0.877  1.0
[/CIF]
.