The material structure described by MgFe10O9F11 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(3), one O(4), one O(8), one O(9), one F(2), and one F(9) atom to form distorted MgO4F2 octahedra that share corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(6)O4F2 octahedra, edges with two equivalent Fe(2)O2F4 octahedra, edges with two equivalent Fe(3)O2F4 octahedra, and faces with two equivalent Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-45°. There are ten inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(7), one F(1), one F(10), one F(4), and one F(7) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(10)O3F3 octahedra, corners with four equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(2)O2F4 octahedra, and  an edgeedge with one Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 39-53°. In the second Fe site, Fe(2) is bonded to one O(3), one O(8), one F(1), one F(2), one F(7), and one F(9) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(6)O4F2 octahedra, corners with four equivalent Fe(8)O4F2 octahedra,  an edgeedge with one Fe(1)O2F4 octahedra,  an edgeedge with one Fe(3)O2F4 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 47-58°. In the third Fe site, Fe(3) is bonded to one O(4), one O(9), one F(2), one F(3), one F(8), and one F(9) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(7)O3F3 octahedra, corners with four equivalent Fe(8)O4F2 octahedra,  an edgeedge with one Fe(2)O2F4 octahedra,  an edgeedge with one Fe(4)O2F4 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(5), one F(11), one F(3), one F(5), and one F(8) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(7)O3F3 octahedra, corners with four equivalent Fe(9)O3F3 octahedra,  an edgeedge with one Fe(3)O2F4 octahedra, and  an edgeedge with one Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 45-61°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(6), one F(10), one F(11), one F(4), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(10)O3F3 octahedra, corners with four equivalent Fe(9)O3F3 octahedra,  an edgeedge with one Fe(1)O2F4 octahedra, and  an edgeedge with one Fe(4)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 38-60°. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(3), one O(7), one O(8), one F(1), and one F(7) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(2)O2F4 octahedra,  an edgeedge with one Fe(10)O3F3 octahedra, and  an edgeedge with one Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 39-57°. In the seventh Fe site, Fe(7) is bonded to one O(4), one O(5), one O(9), one F(3), one F(5), and one F(8) atom to form FeO3F3 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(3)O2F4 octahedra, corners with four equivalent Fe(4)O2F4 octahedra,  an edgeedge with one Fe(9)O3F3 octahedra, and  an edgeedge with one Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. In the eighth Fe site, Fe(8) is bonded to one O(3), one O(4), one O(8), one O(9), one F(2), and one F(9) atom to form distorted FeO4F2 octahedra that share corners with four equivalent Fe(2)O2F4 octahedra, corners with four equivalent Fe(3)O2F4 octahedra,  an edgeedge with one Fe(7)O3F3 octahedra,  an edgeedge with one Fe(6)O4F2 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 45-58°. In the ninth Fe site, Fe(9) is bonded to one O(1), one O(5), one O(6), one F(11), one F(5), and one F(6) atom to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(4)O2F4 octahedra, corners with four equivalent Fe(5)O2F4 octahedra,  an edgeedge with one Fe(10)O3F3 octahedra, and  an edgeedge with one Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-61°. In the tenth Fe site, Fe(10) is bonded to one O(2), one O(6), one O(7), one F(10), one F(4), and one F(6) atom to form FeO3F3 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(5)O2F4 octahedra,  an edgeedge with one Fe(9)O3F3 octahedra, and  an edgeedge with one Fe(6)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-53°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(4), one Fe(5), and one Fe(9) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(6), and one Fe(8) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(3), one Fe(7), and one Fe(8) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(4), one Fe(7), and one Fe(9) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(10), one Fe(5), and one Fe(9) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(6), and one Fe(8) atom. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(3), one Fe(7), and one Fe(8) atom. There are eleven inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(6) atom. In the second F site, F(2) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing FMgFe3 trigonal pyramids. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(4), and one Fe(7) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(5) atom. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(7), and one Fe(9) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Fe(10), one Fe(5), and one Fe(9) atom. In the seventh F site, F(7) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(6) atom. In the eighth F site, F(8) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(4), and one Fe(7) atom. In the ninth F site, F(9) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing FMgFe3 trigonal pyramids. In the tenth F site, F(10) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(5) atom. In the eleventh F site, F(11) is bonded in a 3-coordinate geometry to one Fe(4), one Fe(5), and one Fe(9) atom. is represented by the CIF file [CIF]
data_MgFe10O9F11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.908
_cell_length_b   4.904
_cell_length_c   15.301
_cell_angle_alpha   90.233
_cell_angle_beta   89.947
_cell_angle_gamma   95.602
_symmetry_Int_Tables_number   1
_cell_volume   366.532
_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  0.493  0.996  0.290  1.0
  Fe  Fe1  1  0.991  0.990  0.997  1.0
  Fe  Fe2  1  0.995  0.997  0.186  1.0
  Fe  Fe3  1  0.995  0.990  0.410  1.0
  Fe  Fe4  1  0.031  0.018  0.605  1.0
  Fe  Fe5  1  0.040  0.013  0.791  1.0
  Fe  Fe6  1  0.493  0.497  0.101  1.0
  Fe  Fe7  1  0.494  0.483  0.493  1.0
  Fe  Fe8  1  0.500  0.497  0.298  1.0
  Fe  Fe9  1  0.447  0.530  0.700  1.0
  Fe  Fe10  1  0.505  0.468  0.907  1.0
  O  O11  1  0.202  0.808  0.704  1.0
  O  O12  1  0.302  0.281  0.001  1.0
  O  O13  1  0.340  0.252  0.199  1.0
  O  O14  1  0.332  0.241  0.397  1.0
  O  O15  1  0.330  0.322  0.596  1.0
  O  O16  1  0.318  0.319  0.803  1.0
  O  O17  1  0.687  0.699  0.998  1.0
  O  O18  1  0.650  0.743  0.198  1.0
  O  O19  1  0.662  0.743  0.400  1.0
  F  F20  1  0.175  0.766  0.089  1.0
  F  F21  1  0.146  0.773  0.305  1.0
  F  F22  1  0.178  0.767  0.497  1.0
  F  F23  1  0.179  0.812  0.897  1.0
  F  F24  1  0.697  0.721  0.597  1.0
  F  F25  1  0.704  0.711  0.800  1.0
  F  F26  1  0.812  0.222  0.088  1.0
  F  F27  1  0.826  0.231  0.497  1.0
  F  F28  1  0.845  0.212  0.306  1.0
  F  F29  1  0.814  0.191  0.897  1.0
  F  F30  1  0.815  0.206  0.707  1.0
[/CIF]
.
The material structure described by MgFe10O9F11 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(3), one O(4), one O(8), one O(9), one F(2), and one F(9) atom to form distorted MgO4F2 octahedra that share corners with two equivalent Fe(7)O3F3 octahedra, corners with two equivalent Fe(6)O4F2 octahedra, edges with two equivalent Fe(2)O2F4 octahedra, edges with two equivalent Fe(3)O2F4 octahedra, and faces with two equivalent Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-45°. There are ten inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(7), one F(1), one F(10), one F(4), and one F(7) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(10)O3F3 octahedra, corners with four equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(2)O2F4 octahedra, and  an edgeedge with one Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 39-53°. In the second Fe site, Fe(2) is bonded to one O(3), one O(8), one F(1), one F(2), one F(7), and one F(9) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(6)O4F2 octahedra, corners with four equivalent Fe(8)O4F2 octahedra,  an edgeedge with one Fe(1)O2F4 octahedra,  an edgeedge with one Fe(3)O2F4 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 47-58°. In the third Fe site, Fe(3) is bonded to one O(4), one O(9), one F(2), one F(3), one F(8), and one F(9) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(7)O3F3 octahedra, corners with four equivalent Fe(8)O4F2 octahedra,  an edgeedge with one Fe(2)O2F4 octahedra,  an edgeedge with one Fe(4)O2F4 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(5), one F(11), one F(3), one F(5), and one F(8) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(7)O3F3 octahedra, corners with four equivalent Fe(9)O3F3 octahedra,  an edgeedge with one Fe(3)O2F4 octahedra, and  an edgeedge with one Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 45-61°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(6), one F(10), one F(11), one F(4), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(10)O3F3 octahedra, corners with four equivalent Fe(9)O3F3 octahedra,  an edgeedge with one Fe(1)O2F4 octahedra, and  an edgeedge with one Fe(4)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 38-60°. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(3), one O(7), one O(8), one F(1), and one F(7) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(2)O2F4 octahedra,  an edgeedge with one Fe(10)O3F3 octahedra, and  an edgeedge with one Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 39-57°. In the seventh Fe site, Fe(7) is bonded to one O(4), one O(5), one O(9), one F(3), one F(5), and one F(8) atom to form FeO3F3 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(3)O2F4 octahedra, corners with four equivalent Fe(4)O2F4 octahedra,  an edgeedge with one Fe(9)O3F3 octahedra, and  an edgeedge with one Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. In the eighth Fe site, Fe(8) is bonded to one O(3), one O(4), one O(8), one O(9), one F(2), and one F(9) atom to form distorted FeO4F2 octahedra that share corners with four equivalent Fe(2)O2F4 octahedra, corners with four equivalent Fe(3)O2F4 octahedra,  an edgeedge with one Fe(7)O3F3 octahedra,  an edgeedge with one Fe(6)O4F2 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 45-58°. In the ninth Fe site, Fe(9) is bonded to one O(1), one O(5), one O(6), one F(11), one F(5), and one F(6) atom to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(4)O2F4 octahedra, corners with four equivalent Fe(5)O2F4 octahedra,  an edgeedge with one Fe(10)O3F3 octahedra, and  an edgeedge with one Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-61°. In the tenth Fe site, Fe(10) is bonded to one O(2), one O(6), one O(7), one F(10), one F(4), and one F(6) atom to form FeO3F3 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(5)O2F4 octahedra,  an edgeedge with one Fe(9)O3F3 octahedra, and  an edgeedge with one Fe(6)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 44-53°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(4), one Fe(5), and one Fe(9) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(6), and one Fe(8) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(3), one Fe(7), and one Fe(8) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(4), one Fe(7), and one Fe(9) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(10), one Fe(5), and one Fe(9) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(6), and one Fe(8) atom. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(3), one Fe(7), and one Fe(8) atom. There are eleven inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(6) atom. In the second F site, F(2) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing FMgFe3 trigonal pyramids. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(4), and one Fe(7) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(5) atom. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(4), one Fe(7), and one Fe(9) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Fe(10), one Fe(5), and one Fe(9) atom. In the seventh F site, F(7) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(6) atom. In the eighth F site, F(8) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(4), and one Fe(7) atom. In the ninth F site, F(9) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(8) atom to form a mixture of distorted edge and corner-sharing FMgFe3 trigonal pyramids. In the tenth F site, F(10) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(10), and one Fe(5) atom. In the eleventh F site, F(11) is bonded in a 3-coordinate geometry to one Fe(4), one Fe(5), and one Fe(9) atom. is represented by the CIF file [CIF]
data_MgFe10O9F11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.908
_cell_length_b   4.904
_cell_length_c   15.301
_cell_angle_alpha   90.233
_cell_angle_beta   89.947
_cell_angle_gamma   95.602
_symmetry_Int_Tables_number   1
_cell_volume   366.532
_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  0.493  0.996  0.290  1.0
  Fe  Fe1  1  0.991  0.990  0.997  1.0
  Fe  Fe2  1  0.995  0.997  0.186  1.0
  Fe  Fe3  1  0.995  0.990  0.410  1.0
  Fe  Fe4  1  0.031  0.018  0.605  1.0
  Fe  Fe5  1  0.040  0.013  0.791  1.0
  Fe  Fe6  1  0.493  0.497  0.101  1.0
  Fe  Fe7  1  0.494  0.483  0.493  1.0
  Fe  Fe8  1  0.500  0.497  0.298  1.0
  Fe  Fe9  1  0.447  0.530  0.700  1.0
  Fe  Fe10  1  0.505  0.468  0.907  1.0
  O  O11  1  0.202  0.808  0.704  1.0
  O  O12  1  0.302  0.281  0.001  1.0
  O  O13  1  0.340  0.252  0.199  1.0
  O  O14  1  0.332  0.241  0.397  1.0
  O  O15  1  0.330  0.322  0.596  1.0
  O  O16  1  0.318  0.319  0.803  1.0
  O  O17  1  0.687  0.699  0.998  1.0
  O  O18  1  0.650  0.743  0.198  1.0
  O  O19  1  0.662  0.743  0.400  1.0
  F  F20  1  0.175  0.766  0.089  1.0
  F  F21  1  0.146  0.773  0.305  1.0
  F  F22  1  0.178  0.767  0.497  1.0
  F  F23  1  0.179  0.812  0.897  1.0
  F  F24  1  0.697  0.721  0.597  1.0
  F  F25  1  0.704  0.711  0.800  1.0
  F  F26  1  0.812  0.222  0.088  1.0
  F  F27  1  0.826  0.231  0.497  1.0
  F  F28  1  0.845  0.212  0.306  1.0
  F  F29  1  0.814  0.191  0.897  1.0
  F  F30  1  0.815  0.206  0.707  1.0
[/CIF]
.