The material described by MgTi4Pb2O9F2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(4) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(3), one O(5), two equivalent O(1), and one F(1) atom to form distorted TiO5F octahedra that share corners with three equivalent Ti(1)O5F octahedra,  a cornercorner with one Ti(2)O5 trigonal bipyramid, and edges with two equivalent Ti(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-29°. In the second Ti site, Ti(2) is bonded to one O(1), one O(4), one O(5), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share  a cornercorner with one Ti(1)O5F octahedra, corners with two equivalent Ti(2)O5 trigonal bipyramids, and edges with two equivalent Ti(1)O5F octahedra. The corner-sharing octahedral tilt angles are 9°. Pb(1) is bonded in a 5-coordinate geometry to two equivalent O(4) and three equivalent F(1) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Ti(2) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Ti(1), and two equivalent Ti(2) atoms to form distorted OMgTi3 trigonal pyramids that share corners with two equivalent O(4)Mg2TiPb2 square pyramids,  a cornercorner with one F(1)TiPb3 tetrahedra, corners with three equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(4)Mg2TiPb2 square pyramids. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Ti(2), and two equivalent Pb(1) atoms to form distorted OMg2TiPb2 square pyramids that share corners with two equivalent O(4)Mg2TiPb2 square pyramids, corners with four equivalent F(1)TiPb3 tetrahedra, corners with two equivalent O(2)MgTi3 trigonal pyramids, edges with three equivalent O(4)Mg2TiPb2 square pyramids,  an edgeedge with one F(1)TiPb3 tetrahedra, and edges with two equivalent O(2)MgTi3 trigonal pyramids. In the fifth O site, O(5) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom. F(1) is bonded to one Ti(1) and three equivalent Pb(1) atoms to form distorted FTiPb3 tetrahedra that share corners with four equivalent O(4)Mg2TiPb2 square pyramids, corners with two equivalent F(1)TiPb3 tetrahedra,  a cornercorner with one O(2)MgTi3 trigonal pyramid,  an edgeedge with one O(4)Mg2TiPb2 square pyramid, and edges with two equivalent F(1)TiPb3 tetrahedra. is represented by the CIF file [CIF]
data_MgTi4Pb2O9F2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.759
_cell_length_b   8.611
_cell_length_c   7.989
_cell_angle_alpha   88.157
_cell_angle_beta   76.393
_cell_angle_gamma   77.393
_symmetry_Int_Tables_number   1
_cell_volume   245.225
_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  0.000  0.500  0.500  1.0
  Ti  Ti1  1  0.338  0.117  0.208  1.0
  Ti  Ti2  1  0.662  0.883  0.792  1.0
  Ti  Ti3  1  0.355  0.781  0.508  1.0
  Ti  Ti4  1  0.645  0.219  0.492  1.0
  Pb  Pb5  1  0.912  0.314  0.861  1.0
  Pb  Pb6  1  0.088  0.686  0.139  1.0
  O  O7  1  0.799  0.171  0.232  1.0
  O  O8  1  0.201  0.829  0.768  1.0
  O  O9  1  0.146  0.270  0.438  1.0
  O  O10  1  0.854  0.730  0.562  1.0
  O  O11  1  0.500  0.000  0.000  1.0
  O  O12  1  0.526  0.593  0.355  1.0
  O  O13  1  0.474  0.407  0.645  1.0
  O  O14  1  0.360  0.932  0.348  1.0
  O  O15  1  0.640  0.068  0.652  1.0
  F  F16  1  0.281  0.373  0.065  1.0
  F  F17  1  0.719  0.627  0.935  1.0
[/CIF]
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The material described by MgTi4Pb2O9F2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(4) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(3), one O(5), two equivalent O(1), and one F(1) atom to form distorted TiO5F octahedra that share corners with three equivalent Ti(1)O5F octahedra,  a cornercorner with one Ti(2)O5 trigonal bipyramid, and edges with two equivalent Ti(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-29°. In the second Ti site, Ti(2) is bonded to one O(1), one O(4), one O(5), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share  a cornercorner with one Ti(1)O5F octahedra, corners with two equivalent Ti(2)O5 trigonal bipyramids, and edges with two equivalent Ti(1)O5F octahedra. The corner-sharing octahedral tilt angles are 9°. Pb(1) is bonded in a 5-coordinate geometry to two equivalent O(4) and three equivalent F(1) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Ti(2) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Ti(1), and two equivalent Ti(2) atoms to form distorted OMgTi3 trigonal pyramids that share corners with two equivalent O(4)Mg2TiPb2 square pyramids,  a cornercorner with one F(1)TiPb3 tetrahedra, corners with three equivalent O(2)MgTi3 trigonal pyramids, and edges with two equivalent O(4)Mg2TiPb2 square pyramids. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Ti(2), and two equivalent Pb(1) atoms to form distorted OMg2TiPb2 square pyramids that share corners with two equivalent O(4)Mg2TiPb2 square pyramids, corners with four equivalent F(1)TiPb3 tetrahedra, corners with two equivalent O(2)MgTi3 trigonal pyramids, edges with three equivalent O(4)Mg2TiPb2 square pyramids,  an edgeedge with one F(1)TiPb3 tetrahedra, and edges with two equivalent O(2)MgTi3 trigonal pyramids. In the fifth O site, O(5) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom. F(1) is bonded to one Ti(1) and three equivalent Pb(1) atoms to form distorted FTiPb3 tetrahedra that share corners with four equivalent O(4)Mg2TiPb2 square pyramids, corners with two equivalent F(1)TiPb3 tetrahedra,  a cornercorner with one O(2)MgTi3 trigonal pyramid,  an edgeedge with one O(4)Mg2TiPb2 square pyramid, and edges with two equivalent F(1)TiPb3 tetrahedra. is represented by the CIF file [CIF]
data_MgTi4Pb2O9F2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.759
_cell_length_b   8.611
_cell_length_c   7.989
_cell_angle_alpha   88.157
_cell_angle_beta   76.393
_cell_angle_gamma   77.393
_symmetry_Int_Tables_number   1
_cell_volume   245.225
_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  0.000  0.500  0.500  1.0
  Ti  Ti1  1  0.338  0.117  0.208  1.0
  Ti  Ti2  1  0.662  0.883  0.792  1.0
  Ti  Ti3  1  0.355  0.781  0.508  1.0
  Ti  Ti4  1  0.645  0.219  0.492  1.0
  Pb  Pb5  1  0.912  0.314  0.861  1.0
  Pb  Pb6  1  0.088  0.686  0.139  1.0
  O  O7  1  0.799  0.171  0.232  1.0
  O  O8  1  0.201  0.829  0.768  1.0
  O  O9  1  0.146  0.270  0.438  1.0
  O  O10  1  0.854  0.730  0.562  1.0
  O  O11  1  0.500  0.000  0.000  1.0
  O  O12  1  0.526  0.593  0.355  1.0
  O  O13  1  0.474  0.407  0.645  1.0
  O  O14  1  0.360  0.932  0.348  1.0
  O  O15  1  0.640  0.068  0.652  1.0
  F  F16  1  0.281  0.373  0.065  1.0
  F  F17  1  0.719  0.627  0.935  1.0
[/CIF]
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