The compound described by MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(12), one O(13), one O(6), one O(7), and one F(1) atom to form MgO5F octahedra that share corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra,  a cornercorner with one Fe(6)O4F square pyramid,  a cornercorner with one Fe(5)O5 square pyramid,  a faceface with one Fe(2)O5F octahedra, and  a faceface with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 39-45°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(5), and one F(1) atom to form FeO5F octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra, corners with two equivalent Fe(6)O4F square pyramids, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(2)O5F octahedra, and  an edgeedge with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 44-52°. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(3), one O(4), one O(7), and one F(2) atom to form FeO5F octahedra that share corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(5)O5 square pyramid, corners with two equivalent Fe(6)O4F square pyramids,  an edgeedge with one Fe(1)O5F octahedra,  an edgeedge with one Fe(7)O6 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 47-54°. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one F(2) atom to form FeO5F octahedra that share corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra,  an edgeedge with one Fe(6)O4F square pyramid, and  an edgeedge with one Fe(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 37-55°. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(6), one O(7), one O(9), and one F(1) atom. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form FeO5 square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(2)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra, and  an edgeedge with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 45-74°. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(14), one O(2), one O(7), and one F(2) atom to form distorted FeO4F square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(8)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, and  an edgeedge with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-76°. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(12), one O(13), one O(14), one O(4), and one O(9) atom to form FeO6 octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(6)O4F square pyramid,  a cornercorner with one Fe(5)O5 square pyramid,  an edgeedge with one Fe(2)O5F octahedra, and  an edgeedge with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 37-44°. In the eighth Fe site, Fe(8) is bonded to one O(11), one O(13), one O(2), one O(6), one O(8), and one F(1) atom to form distorted FeO5F octahedra that share corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(6)O4F square pyramid, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(1)O5F octahedra,  an edgeedge with one Fe(7)O6 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-55°. 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(3), and one Fe(6) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1), one Fe(6), and one Fe(8) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(7) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(4), one Fe(5), and one Fe(8) atom to form distorted corner-sharing OMgFe3 trigonal pyramids. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom to form distorted corner-sharing OMgFe3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(8) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(5), and one Fe(7) atom. In the tenth O site, O(10) is bonded in a distorted see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(7), and one Fe(8) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(7) atom. In the thirteenth O site, O(13) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(7), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(8) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom. is represented by the CIF file [CIF]
data_MgFe8(O7F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.282
_cell_length_b   7.771
_cell_length_c   5.818
_cell_angle_alpha   113.217
_cell_angle_beta   110.458
_cell_angle_gamma   79.202
_symmetry_Int_Tables_number   1
_cell_volume   283.001
_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  0.743  0.736  0.973  1.0
  Fe  Fe1  1  0.747  0.236  0.501  1.0
  Fe  Fe2  1  0.478  0.022  0.976  1.0
  Fe  Fe3  1  0.241  0.264  0.530  1.0
  Fe  Fe4  1  0.730  0.783  0.475  1.0
  Fe  Fe5  1  0.504  0.469  0.036  1.0
  Fe  Fe6  1  0.976  0.033  0.983  1.0
  Fe  Fe7  1  0.233  0.755  0.505  1.0
  Fe  Fe8  1  0.034  0.466  0.053  1.0
  O  O9  1  0.975  0.184  0.347  1.0
  O  O10  1  0.923  0.229  0.840  1.0
  O  O11  1  0.563  0.266  0.174  1.0
  O  O12  1  0.303  0.031  0.654  1.0
  O  O13  1  0.519  0.319  0.685  1.0
  O  O14  1  0.760  0.566  0.163  1.0
  O  O15  1  0.716  0.932  0.825  1.0
  O  O16  1  0.235  0.427  0.882  1.0
  O  O17  1  0.475  0.679  0.344  1.0
  O  O18  1  0.670  0.966  0.291  1.0
  O  O19  1  0.193  0.476  0.393  1.0
  O  O20  1  0.432  0.766  0.838  1.0
  O  O21  1  0.047  0.737  0.166  1.0
  O  O22  1  0.005  0.829  0.656  1.0
  F  F23  1  0.808  0.521  0.682  1.0
  F  F24  1  0.265  0.076  0.162  1.0
[/CIF]
.
The compound described by MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(12), one O(13), one O(6), one O(7), and one F(1) atom to form MgO5F octahedra that share corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra,  a cornercorner with one Fe(6)O4F square pyramid,  a cornercorner with one Fe(5)O5 square pyramid,  a faceface with one Fe(2)O5F octahedra, and  a faceface with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 39-45°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(5), and one F(1) atom to form FeO5F octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra, corners with two equivalent Fe(6)O4F square pyramids, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(2)O5F octahedra, and  an edgeedge with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 44-52°. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(3), one O(4), one O(7), and one F(2) atom to form FeO5F octahedra that share corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(5)O5 square pyramid, corners with two equivalent Fe(6)O4F square pyramids,  an edgeedge with one Fe(1)O5F octahedra,  an edgeedge with one Fe(7)O6 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 47-54°. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one F(2) atom to form FeO5F octahedra that share corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra,  an edgeedge with one Fe(6)O4F square pyramid, and  an edgeedge with one Fe(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 37-55°. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(6), one O(7), one O(9), and one F(1) atom. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form FeO5 square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(2)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra, and  an edgeedge with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 45-74°. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(14), one O(2), one O(7), and one F(2) atom to form distorted FeO4F square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(8)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, and  an edgeedge with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-76°. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(12), one O(13), one O(14), one O(4), and one O(9) atom to form FeO6 octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(6)O4F square pyramid,  a cornercorner with one Fe(5)O5 square pyramid,  an edgeedge with one Fe(2)O5F octahedra, and  an edgeedge with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 37-44°. In the eighth Fe site, Fe(8) is bonded to one O(11), one O(13), one O(2), one O(6), one O(8), and one F(1) atom to form distorted FeO5F octahedra that share corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(6)O4F square pyramid, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(1)O5F octahedra,  an edgeedge with one Fe(7)O6 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-55°. 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(3), and one Fe(6) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1), one Fe(6), and one Fe(8) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(7) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(4), one Fe(5), and one Fe(8) atom to form distorted corner-sharing OMgFe3 trigonal pyramids. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom to form distorted corner-sharing OMgFe3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(8) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(5), and one Fe(7) atom. In the tenth O site, O(10) is bonded in a distorted see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(7), and one Fe(8) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(7) atom. In the thirteenth O site, O(13) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(7), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(8) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom. is represented by the CIF file [CIF]
data_MgFe8(O7F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.282
_cell_length_b   7.771
_cell_length_c   5.818
_cell_angle_alpha   113.217
_cell_angle_beta   110.458
_cell_angle_gamma   79.202
_symmetry_Int_Tables_number   1
_cell_volume   283.001
_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  0.743  0.736  0.973  1.0
  Fe  Fe1  1  0.747  0.236  0.501  1.0
  Fe  Fe2  1  0.478  0.022  0.976  1.0
  Fe  Fe3  1  0.241  0.264  0.530  1.0
  Fe  Fe4  1  0.730  0.783  0.475  1.0
  Fe  Fe5  1  0.504  0.469  0.036  1.0
  Fe  Fe6  1  0.976  0.033  0.983  1.0
  Fe  Fe7  1  0.233  0.755  0.505  1.0
  Fe  Fe8  1  0.034  0.466  0.053  1.0
  O  O9  1  0.975  0.184  0.347  1.0
  O  O10  1  0.923  0.229  0.840  1.0
  O  O11  1  0.563  0.266  0.174  1.0
  O  O12  1  0.303  0.031  0.654  1.0
  O  O13  1  0.519  0.319  0.685  1.0
  O  O14  1  0.760  0.566  0.163  1.0
  O  O15  1  0.716  0.932  0.825  1.0
  O  O16  1  0.235  0.427  0.882  1.0
  O  O17  1  0.475  0.679  0.344  1.0
  O  O18  1  0.670  0.966  0.291  1.0
  O  O19  1  0.193  0.476  0.393  1.0
  O  O20  1  0.432  0.766  0.838  1.0
  O  O21  1  0.047  0.737  0.166  1.0
  O  O22  1  0.005  0.829  0.656  1.0
  F  F23  1  0.808  0.521  0.682  1.0
  F  F24  1  0.265  0.076  0.162  1.0
[/CIF]
.