The crystal structure described by MgTi4Pb2O9F2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one Pb(1), one O(1), one O(6), one F(2), and two equivalent F(1) atoms to form distorted MgPbO2F3 square pyramids that share  a cornercorner with one Ti(2)O5F octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Mg(1)PbO2F3 square pyramids,  an edgeedge with one Ti(4)O6 octahedra, and edges with two equivalent Ti(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 1-5°. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(3), one O(5), one O(8), two equivalent O(1), and one F(1) atom to form distorted TiO5F octahedra that share  a cornercorner with one Ti(2)O5F octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(1)O5F octahedra, edges with two equivalent Ti(4)O6 octahedra, and edges with two equivalent Mg(1)PbO2F3 square pyramids. The corner-sharing octahedral tilt angles range from 8-32°. In the second Ti site, Ti(2) is bonded to one O(4), one O(5), one O(9), two equivalent O(2), and one F(2) atom to form TiO5F octahedra that share  a cornercorner with one Ti(1)O5F octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with two equivalent Ti(2)O5F octahedra,  a cornercorner with one Mg(1)PbO2F3 square pyramid, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-16°. In the third Ti site, Ti(3) is bonded to one O(2), one O(6), one O(7), one O(8), and two equivalent O(4) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(1)O5F octahedra, corners with two equivalent Ti(3)O6 octahedra,  a cornercorner with one Mg(1)PbO2F3 square pyramid,  an edgeedge with one Ti(4)O6 octahedra, and edges with two equivalent Ti(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 10-18°. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(6), one O(7), one O(9), and two equivalent O(3) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(2)O5F octahedra, corners with two equivalent Ti(4)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, edges with two equivalent Ti(1)O5F octahedra, and  an edgeedge with one Mg(1)PbO2F3 square pyramid. The corner-sharing octahedral tilt angles range from 6-12°. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 7-coordinate geometry to one Mg(1), one O(2), one O(3), two equivalent O(7), and two equivalent O(9) atoms. In the second Pb site, Pb(2) is bonded in a distorted pentagonal planar geometry to one O(4), two equivalent O(6), and two equivalent O(8) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ti(4), and two equivalent Ti(1) atoms to form corner-sharing OMgTi3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ti(3), two equivalent Ti(2), and one Pb(1) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Ti(1), two equivalent Ti(4), and one Pb(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(3), and one Pb(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Ti(3), one Ti(4), and two equivalent Pb(2) atoms. In the seventh O site, O(7) is bonded in a water-like geometry to one Ti(3), one Ti(4), and two equivalent Pb(1) atoms. In the eighth O site, O(8) is bonded in a distorted see-saw-like geometry to one Ti(1), one Ti(3), and two equivalent Pb(2) atoms. In the ninth O site, O(9) is bonded in a distorted see-saw-like geometry to one Ti(2), one Ti(4), and two equivalent Pb(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to two equivalent Mg(1) and one Ti(1) atom. In the second F site, F(2) is bonded in a linear geometry to one Mg(1) and one Ti(2) atom. is represented by the CIF card [CIF]
data_MgTi4Pb2O9F2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.967
_cell_length_b   7.835
_cell_length_c   7.869
_cell_angle_alpha   84.062
_cell_angle_beta   75.401
_cell_angle_gamma   75.337
_symmetry_Int_Tables_number   1
_cell_volume   228.744
_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  0.732  0.437  0.099  1.0
  Ti  Ti1  1  0.332  0.111  0.224  1.0
  Ti  Ti2  1  0.671  0.875  0.784  1.0
  Ti  Ti3  1  0.380  0.675  0.565  1.0
  Ti  Ti4  1  0.621  0.297  0.461  1.0
  Pb  Pb5  1  0.010  0.209  0.772  1.0
  Pb  Pb6  1  0.006  0.758  0.231  1.0
  O  O7  1  0.800  0.185  0.216  1.0
  O  O8  1  0.195  0.854  0.756  1.0
  O  O9  1  0.140  0.273  0.447  1.0
  O  O10  1  0.861  0.716  0.562  1.0
  O  O11  1  0.499  0.008  0.994  1.0
  O  O12  1  0.562  0.542  0.333  1.0
  O  O13  1  0.442  0.450  0.665  1.0
  O  O14  1  0.370  0.904  0.356  1.0
  O  O15  1  0.637  0.091  0.634  1.0
  F  F16  1  0.270  0.388  0.073  1.0
  F  F17  1  0.704  0.645  0.947  1.0
[/CIF]
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The crystal structure described by MgTi4Pb2O9F2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one Pb(1), one O(1), one O(6), one F(2), and two equivalent F(1) atoms to form distorted MgPbO2F3 square pyramids that share  a cornercorner with one Ti(2)O5F octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Mg(1)PbO2F3 square pyramids,  an edgeedge with one Ti(4)O6 octahedra, and edges with two equivalent Ti(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 1-5°. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(3), one O(5), one O(8), two equivalent O(1), and one F(1) atom to form distorted TiO5F octahedra that share  a cornercorner with one Ti(2)O5F octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(1)O5F octahedra, edges with two equivalent Ti(4)O6 octahedra, and edges with two equivalent Mg(1)PbO2F3 square pyramids. The corner-sharing octahedral tilt angles range from 8-32°. In the second Ti site, Ti(2) is bonded to one O(4), one O(5), one O(9), two equivalent O(2), and one F(2) atom to form TiO5F octahedra that share  a cornercorner with one Ti(1)O5F octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with two equivalent Ti(2)O5F octahedra,  a cornercorner with one Mg(1)PbO2F3 square pyramid, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-16°. In the third Ti site, Ti(3) is bonded to one O(2), one O(6), one O(7), one O(8), and two equivalent O(4) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(1)O5F octahedra, corners with two equivalent Ti(3)O6 octahedra,  a cornercorner with one Mg(1)PbO2F3 square pyramid,  an edgeedge with one Ti(4)O6 octahedra, and edges with two equivalent Ti(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 10-18°. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(6), one O(7), one O(9), and two equivalent O(3) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(2)O5F octahedra, corners with two equivalent Ti(4)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, edges with two equivalent Ti(1)O5F octahedra, and  an edgeedge with one Mg(1)PbO2F3 square pyramid. The corner-sharing octahedral tilt angles range from 6-12°. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 7-coordinate geometry to one Mg(1), one O(2), one O(3), two equivalent O(7), and two equivalent O(9) atoms. In the second Pb site, Pb(2) is bonded in a distorted pentagonal planar geometry to one O(4), two equivalent O(6), and two equivalent O(8) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ti(4), and two equivalent Ti(1) atoms to form corner-sharing OMgTi3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ti(3), two equivalent Ti(2), and one Pb(1) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Ti(1), two equivalent Ti(4), and one Pb(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(3), and one Pb(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Ti(3), one Ti(4), and two equivalent Pb(2) atoms. In the seventh O site, O(7) is bonded in a water-like geometry to one Ti(3), one Ti(4), and two equivalent Pb(1) atoms. In the eighth O site, O(8) is bonded in a distorted see-saw-like geometry to one Ti(1), one Ti(3), and two equivalent Pb(2) atoms. In the ninth O site, O(9) is bonded in a distorted see-saw-like geometry to one Ti(2), one Ti(4), and two equivalent Pb(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to two equivalent Mg(1) and one Ti(1) atom. In the second F site, F(2) is bonded in a linear geometry to one Mg(1) and one Ti(2) atom. is represented by the CIF card [CIF]
data_MgTi4Pb2O9F2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.967
_cell_length_b   7.835
_cell_length_c   7.869
_cell_angle_alpha   84.062
_cell_angle_beta   75.401
_cell_angle_gamma   75.337
_symmetry_Int_Tables_number   1
_cell_volume   228.744
_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  0.732  0.437  0.099  1.0
  Ti  Ti1  1  0.332  0.111  0.224  1.0
  Ti  Ti2  1  0.671  0.875  0.784  1.0
  Ti  Ti3  1  0.380  0.675  0.565  1.0
  Ti  Ti4  1  0.621  0.297  0.461  1.0
  Pb  Pb5  1  0.010  0.209  0.772  1.0
  Pb  Pb6  1  0.006  0.758  0.231  1.0
  O  O7  1  0.800  0.185  0.216  1.0
  O  O8  1  0.195  0.854  0.756  1.0
  O  O9  1  0.140  0.273  0.447  1.0
  O  O10  1  0.861  0.716  0.562  1.0
  O  O11  1  0.499  0.008  0.994  1.0
  O  O12  1  0.562  0.542  0.333  1.0
  O  O13  1  0.442  0.450  0.665  1.0
  O  O14  1  0.370  0.904  0.356  1.0
  O  O15  1  0.637  0.091  0.634  1.0
  F  F16  1  0.270  0.388  0.073  1.0
  F  F17  1  0.704  0.645  0.947  1.0
[/CIF]
.