The material described by MgTi4Pb2O9F2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) 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  a cornercorner with one Ti(2)O6 octahedra, corners with three equivalent Ti(1)O5F octahedra, and edges with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-17°. In the second Ti site, Ti(2) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(1)O5F octahedra, corners with two equivalent Ti(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 1-17°. Pb(1) is bonded in a 3-coordinate geometry to two equivalent O(4) and one F(1) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ti(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a T-shaped geometry to one Ti(1) and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Ti(2) and two equivalent Pb(1) atoms to form a mixture of distorted edge and corner-sharing OTi2Pb2 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 in a bent 120 degrees geometry to one Ti(1) and one Pb(1) atom. is represented by the CIF file [CIF]
data_MgTi4Pb2O9F2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.017
_cell_length_b   7.761
_cell_length_c   7.872
_cell_angle_alpha   86.626
_cell_angle_beta   75.217
_cell_angle_gamma   75.001
_symmetry_Int_Tables_number   1
_cell_volume   229.242
_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  0.000  0.000  1.0
  Ti  Ti1  1  0.320  0.103  0.257  1.0
  Ti  Ti2  1  0.680  0.897  0.743  1.0
  Ti  Ti3  1  0.370  0.708  0.552  1.0
  Ti  Ti4  1  0.630  0.292  0.448  1.0
  Pb  Pb5  1  0.916  0.370  0.798  1.0
  Pb  Pb6  1  0.084  0.630  0.202  1.0
  O  O7  1  0.819  0.131  0.232  1.0
  O  O8  1  0.181  0.869  0.768  1.0
  O  O9  1  0.131  0.290  0.449  1.0
  O  O10  1  0.869  0.710  0.551  1.0
  O  O11  1  0.500  0.000  0.000  1.0
  O  O12  1  0.569  0.527  0.334  1.0
  O  O13  1  0.431  0.473  0.666  1.0
  O  O14  1  0.369  0.893  0.368  1.0
  O  O15  1  0.631  0.107  0.632  1.0
  F  F16  1  0.286  0.350  0.078  1.0
  F  F17  1  0.714  0.650  0.922  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 square co-planar geometry to two equivalent O(1) and two equivalent O(3) 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  a cornercorner with one Ti(2)O6 octahedra, corners with three equivalent Ti(1)O5F octahedra, and edges with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-17°. In the second Ti site, Ti(2) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(1)O5F octahedra, corners with two equivalent Ti(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 1-17°. Pb(1) is bonded in a 3-coordinate geometry to two equivalent O(4) and one F(1) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ti(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a T-shaped geometry to one Ti(1) and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Ti(2) and two equivalent Pb(1) atoms to form a mixture of distorted edge and corner-sharing OTi2Pb2 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 in a bent 120 degrees geometry to one Ti(1) and one Pb(1) atom. is represented by the CIF file [CIF]
data_MgTi4Pb2O9F2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.017
_cell_length_b   7.761
_cell_length_c   7.872
_cell_angle_alpha   86.626
_cell_angle_beta   75.217
_cell_angle_gamma   75.001
_symmetry_Int_Tables_number   1
_cell_volume   229.242
_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  0.000  0.000  1.0
  Ti  Ti1  1  0.320  0.103  0.257  1.0
  Ti  Ti2  1  0.680  0.897  0.743  1.0
  Ti  Ti3  1  0.370  0.708  0.552  1.0
  Ti  Ti4  1  0.630  0.292  0.448  1.0
  Pb  Pb5  1  0.916  0.370  0.798  1.0
  Pb  Pb6  1  0.084  0.630  0.202  1.0
  O  O7  1  0.819  0.131  0.232  1.0
  O  O8  1  0.181  0.869  0.768  1.0
  O  O9  1  0.131  0.290  0.449  1.0
  O  O10  1  0.869  0.710  0.551  1.0
  O  O11  1  0.500  0.000  0.000  1.0
  O  O12  1  0.569  0.527  0.334  1.0
  O  O13  1  0.431  0.473  0.666  1.0
  O  O14  1  0.369  0.893  0.368  1.0
  O  O15  1  0.631  0.107  0.632  1.0
  F  F16  1  0.286  0.350  0.078  1.0
  F  F17  1  0.714  0.650  0.922  1.0
[/CIF]
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