The compound described by MgFe10O9F11 is zeta iron carbide-derived structured and crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 4-coordinate geometry to one O(3), two equivalent O(6), and two equivalent F(1) atoms. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(5), one F(1), one F(2), one F(4), and one F(5) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(5)O3F3 octahedra, corners with four equivalent Fe(4)O4F2 octahedra, and  an edgeedge with one Fe(3)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 45-53°. In the second Fe site, Fe(2) is bonded in a 4-coordinate geometry to one O(3), one O(6), and two equivalent F(4) atoms. In the third Fe site, Fe(3) is bonded to one O(1), one O(4), one F(2), one F(3), one F(5), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(5)O3F3 octahedra, corners with four equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(1)O2F4 octahedra, and  an edgeedge with one Fe(3)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 40-63°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(5), one O(6), one F(1), and one F(4) atom to form distorted FeO4F2 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra,  an edgeedge with one Fe(5)O3F3 octahedra, and  an edgeedge with one Fe(4)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 45-48°. In the fifth Fe site, Fe(5) is bonded to one O(2), one O(4), one O(5), one F(2), one F(3), and one F(5) atom to form FeO3F3 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(3)O2F4 octahedra,  an edgeedge with one Fe(6)O3F3 octahedra, and  an edgeedge with one Fe(4)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. In the sixth Fe site, Fe(6) is bonded to one O(1), two equivalent O(4), one F(6), and two equivalent F(3) atoms to form FeO3F3 octahedra that share corners with eight equivalent Fe(3)O2F4 octahedra and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 40-63°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), and two equivalent Fe(4) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Fe(2), and two equivalent Fe(4) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one Fe(4) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the sixth F site, F(6) is bonded in a 3-coordinate geometry to one Fe(6) and two equivalent Fe(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe10O9F11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.809
_cell_length_b   4.848
_cell_length_c   15.910
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   95.975
_symmetry_Int_Tables_number   1
_cell_volume   368.862
_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  0.244  0.733  0.200  1.0
  Fe  Fe1  1  0.005  0.982  0.985  1.0
  Fe  Fe2  1  0.890  0.101  0.200  1.0
  Fe  Fe3  1  0.005  0.982  0.415  1.0
  Fe  Fe4  1  0.034  0.012  0.615  1.0
  Fe  Fe5  1  0.034  0.012  0.785  1.0
  Fe  Fe6  1  0.518  0.478  0.085  1.0
  Fe  Fe7  1  0.498  0.478  0.500  1.0
  Fe  Fe8  1  0.518  0.478  0.315  1.0
  Fe  Fe9  1  0.459  0.515  0.700  1.0
  Fe  Fe10  1  0.498  0.478  0.900  1.0
  O  O11  1  0.211  0.801  0.700  1.0
  O  O12  1  0.300  0.282  0.992  1.0
  O  O13  1  0.276  0.312  0.200  1.0
  O  O14  1  0.300  0.282  0.408  1.0
  O  O15  1  0.320  0.320  0.600  1.0
  O  O16  1  0.320  0.320  0.800  1.0
  O  O17  1  0.709  0.687  0.989  1.0
  O  O18  1  0.682  0.713  0.200  1.0
  O  O19  1  0.709  0.687  0.411  1.0
  F  F20  1  0.202  0.789  0.083  1.0
  F  F21  1  0.202  0.789  0.317  1.0
  F  F22  1  0.206  0.798  0.508  1.0
  F  F23  1  0.206  0.798  0.892  1.0
  F  F24  1  0.709  0.711  0.602  1.0
  F  F25  1  0.709  0.711  0.798  1.0
  F  F26  1  0.801  0.184  0.081  1.0
  F  F27  1  0.812  0.185  0.507  1.0
  F  F28  1  0.801  0.184  0.319  1.0
  F  F29  1  0.812  0.185  0.893  1.0
  F  F30  1  0.796  0.220  0.700  1.0
[/CIF]
.
The compound described by MgFe10O9F11 is zeta iron carbide-derived structured and crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 4-coordinate geometry to one O(3), two equivalent O(6), and two equivalent F(1) atoms. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(5), one F(1), one F(2), one F(4), and one F(5) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(5)O3F3 octahedra, corners with four equivalent Fe(4)O4F2 octahedra, and  an edgeedge with one Fe(3)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 45-53°. In the second Fe site, Fe(2) is bonded in a 4-coordinate geometry to one O(3), one O(6), and two equivalent F(4) atoms. In the third Fe site, Fe(3) is bonded to one O(1), one O(4), one F(2), one F(3), one F(5), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(5)O3F3 octahedra, corners with four equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(1)O2F4 octahedra, and  an edgeedge with one Fe(3)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 40-63°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(5), one O(6), one F(1), and one F(4) atom to form distorted FeO4F2 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra,  an edgeedge with one Fe(5)O3F3 octahedra, and  an edgeedge with one Fe(4)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 45-48°. In the fifth Fe site, Fe(5) is bonded to one O(2), one O(4), one O(5), one F(2), one F(3), and one F(5) atom to form FeO3F3 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(3)O2F4 octahedra,  an edgeedge with one Fe(6)O3F3 octahedra, and  an edgeedge with one Fe(4)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. In the sixth Fe site, Fe(6) is bonded to one O(1), two equivalent O(4), one F(6), and two equivalent F(3) atoms to form FeO3F3 octahedra that share corners with eight equivalent Fe(3)O2F4 octahedra and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 40-63°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), and two equivalent Fe(4) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Fe(2), and two equivalent Fe(4) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one Fe(4) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the fifth F site, F(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the sixth F site, F(6) is bonded in a 3-coordinate geometry to one Fe(6) and two equivalent Fe(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe10O9F11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.809
_cell_length_b   4.848
_cell_length_c   15.910
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   95.975
_symmetry_Int_Tables_number   1
_cell_volume   368.862
_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  0.244  0.733  0.200  1.0
  Fe  Fe1  1  0.005  0.982  0.985  1.0
  Fe  Fe2  1  0.890  0.101  0.200  1.0
  Fe  Fe3  1  0.005  0.982  0.415  1.0
  Fe  Fe4  1  0.034  0.012  0.615  1.0
  Fe  Fe5  1  0.034  0.012  0.785  1.0
  Fe  Fe6  1  0.518  0.478  0.085  1.0
  Fe  Fe7  1  0.498  0.478  0.500  1.0
  Fe  Fe8  1  0.518  0.478  0.315  1.0
  Fe  Fe9  1  0.459  0.515  0.700  1.0
  Fe  Fe10  1  0.498  0.478  0.900  1.0
  O  O11  1  0.211  0.801  0.700  1.0
  O  O12  1  0.300  0.282  0.992  1.0
  O  O13  1  0.276  0.312  0.200  1.0
  O  O14  1  0.300  0.282  0.408  1.0
  O  O15  1  0.320  0.320  0.600  1.0
  O  O16  1  0.320  0.320  0.800  1.0
  O  O17  1  0.709  0.687  0.989  1.0
  O  O18  1  0.682  0.713  0.200  1.0
  O  O19  1  0.709  0.687  0.411  1.0
  F  F20  1  0.202  0.789  0.083  1.0
  F  F21  1  0.202  0.789  0.317  1.0
  F  F22  1  0.206  0.798  0.508  1.0
  F  F23  1  0.206  0.798  0.892  1.0
  F  F24  1  0.709  0.711  0.602  1.0
  F  F25  1  0.709  0.711  0.798  1.0
  F  F26  1  0.801  0.184  0.081  1.0
  F  F27  1  0.812  0.185  0.507  1.0
  F  F28  1  0.801  0.184  0.319  1.0
  F  F29  1  0.812  0.185  0.893  1.0
  F  F30  1  0.796  0.220  0.700  1.0
[/CIF]
.