The structure described by MgTiNb2(PbO3)4 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(18), one O(2), one O(23), one O(3), one O(4), and one O(6) atom to form MgO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-16°. In the second Mg site, Mg(2) is bonded to one O(1), one O(13), one O(14), one O(16), one O(19), and one O(7) atom to form MgO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-19°. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(12), one O(15), one O(17), one O(5), and one O(9) atom to form distorted TiO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-16°. In the second Ti site, Ti(2) is bonded to one O(10), one O(20), one O(21), one O(22), one O(24), and one O(8) atom to form distorted TiO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-15°. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(17), one O(21), one O(3), one O(4), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-16°. In the second Nb site, Nb(2) is bonded to one O(10), one O(12), one O(13), one O(15), one O(18), and one O(6) atom to form distorted NbO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-16°. In the third Nb site, Nb(3) is bonded to one O(11), one O(14), one O(16), one O(2), one O(20), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-12°. In the fourth Nb site, Nb(4) is bonded to one O(19), one O(22), one O(23), one O(24), one O(7), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-19°. There are eight inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 6-coordinate geometry to one O(10), one O(14), one O(18), one O(2), one O(22), and one O(8) atom. In the second Pb site, Pb(2) is bonded in a 5-coordinate geometry to one O(1), one O(16), one O(24), one O(7), and one O(9) atom. In the third Pb site, Pb(3) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(2), one O(20), and one O(6) atom. In the fourth Pb site, Pb(4) is bonded in a 6-coordinate geometry to one O(1), one O(16), one O(19), one O(20), one O(24), and one O(9) atom. In the fifth Pb site, Pb(5) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(21), one O(3), and one O(5) atom. In the sixth Pb site, Pb(6) is bonded in a 5-coordinate geometry to one O(13), one O(15), one O(23), one O(4), and one O(6) atom. In the seventh Pb site, Pb(7) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(17), one O(21), and one O(3) atom. In the eighth Pb site, Pb(8) is bonded in a 6-coordinate geometry to one O(13), one O(15), one O(18), one O(19), one O(23), and one O(4) atom. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(2), one Nb(1), one Pb(2), and one Pb(4) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Nb(3), one Pb(1), and one Pb(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Nb(1), one Pb(5), and one Pb(7) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Mg(1), one Nb(1), one Pb(6), and one Pb(8) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ti(1), one Nb(1), and one Pb(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Mg(1), one Nb(2), one Pb(3), and one Pb(6) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(2), one Nb(4), and one Pb(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ti(2), one Nb(3), and one Pb(1) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Ti(1), one Nb(4), one Pb(2), and one Pb(4) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Ti(2), one Nb(2), one Pb(1), and one Pb(3) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Ti(1), one Nb(3), one Pb(5), and one Pb(7) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Ti(1), one Nb(2), one Pb(5), and one Pb(7) atom. In the thirteenth O site, O(13) is bonded in a distorted see-saw-like geometry to one Mg(2), one Nb(2), one Pb(6), and one Pb(8) atom. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to one Mg(2), one Nb(3), one Pb(1), and one Pb(3) atom. In the fifteenth O site, O(15) is bonded in a 1-coordinate geometry to one Ti(1), one Nb(2), one Pb(6), and one Pb(8) atom. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to one Mg(2), one Nb(3), one Pb(2), and one Pb(4) atom. In the seventeenth O site, O(17) is bonded in a distorted T-shaped geometry to one Ti(1), one Nb(1), and one Pb(7) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Mg(1), one Nb(2), one Pb(1), and one Pb(8) atom. In the nineteenth O site, O(19) is bonded in a 3-coordinate geometry to one Mg(2), one Nb(4), one Pb(4), and one Pb(8) atom. In the twentieth O site, O(20) is bonded in a 2-coordinate geometry to one Ti(2), one Nb(3), one Pb(3), and one Pb(4) atom. In the twenty-first O site, O(21) is bonded in a 4-coordinate geometry to one Ti(2), one Nb(1), one Pb(5), and one Pb(7) atom. In the twenty-second O site, O(22) is bonded in a distorted linear geometry to one Ti(2), one Nb(4), and one Pb(1) atom. In the twenty-third O site, O(23) is bonded in a 2-coordinate geometry to one Mg(1), one Nb(4), one Pb(6), and one Pb(8) atom. In the twenty-fourth O site, O(24) is bonded in a 1-coordinate geometry to one Ti(2), one Nb(4), one Pb(2), and one Pb(4) atom. is represented by the CIF card [CIF]
data_MgTiNb2(PbO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.060
_cell_length_b   8.302
_cell_length_c   9.980
_cell_angle_alpha   113.708
_cell_angle_beta   113.745
_cell_angle_gamma   89.852
_symmetry_Int_Tables_number   1
_cell_volume   549.455
_cell_formula_units_Z   2
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  0.389  0.890  0.262  1.0
  Mg  Mg1  1  0.137  0.138  0.758  1.0
  Ti  Ti2  1  0.879  0.376  0.252  1.0
  Ti  Ti3  1  0.631  0.628  0.757  1.0
  Nb  Nb4  1  0.383  0.392  0.258  1.0
  Nb  Nb5  1  0.886  0.878  0.257  1.0
  Nb  Nb6  1  0.130  0.644  0.754  1.0
  Nb  Nb7  1  0.638  0.128  0.760  1.0
  Pb  Pb8  1  0.018  0.975  0.998  1.0
  Pb  Pb9  1  0.000  0.480  0.981  1.0
  Pb  Pb10  1  0.483  0.976  0.995  1.0
  Pb  Pb11  1  0.486  0.482  0.981  1.0
  Pb  Pb12  1  0.738  0.732  0.486  1.0
  Pb  Pb13  1  0.753  0.222  0.488  1.0
  Pb  Pb14  1  0.252  0.735  0.490  1.0
  Pb  Pb15  1  0.241  0.221  0.490  1.0
  O  O16  1  0.273  0.292  0.028  1.0
  O  O17  1  0.265  0.790  0.011  1.0
  O  O18  1  0.408  0.656  0.294  1.0
  O  O19  1  0.403  0.173  0.284  1.0
  O  O20  1  0.654  0.418  0.283  1.0
  O  O21  1  0.649  0.921  0.271  1.0
  O  O22  1  0.892  0.178  0.784  1.0
  O  O23  1  0.892  0.661  0.773  1.0
  O  O24  1  0.774  0.295  0.029  1.0
  O  O25  1  0.769  0.791  0.017  1.0
  O  O26  1  0.020  0.537  0.517  1.0
  O  O27  1  0.896  0.658  0.274  1.0
  O  O28  1  0.013  0.039  0.506  1.0
  O  O29  1  0.150  0.898  0.774  1.0
  O  O30  1  0.894  0.167  0.271  1.0
  O  O31  1  0.151  0.420  0.782  1.0
  O  O32  1  0.146  0.418  0.281  1.0
  O  O33  1  0.137  0.921  0.269  1.0
  O  O34  1  0.408  0.178  0.784  1.0
  O  O35  1  0.400  0.660  0.773  1.0
  O  O36  1  0.527  0.543  0.532  1.0
  O  O37  1  0.646  0.908  0.774  1.0
  O  O38  1  0.523  0.042  0.528  1.0
  O  O39  1  0.651  0.421  0.784  1.0
[/CIF]
.
The structure described by MgTiNb2(PbO3)4 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(18), one O(2), one O(23), one O(3), one O(4), and one O(6) atom to form MgO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-16°. In the second Mg site, Mg(2) is bonded to one O(1), one O(13), one O(14), one O(16), one O(19), and one O(7) atom to form MgO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-19°. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(12), one O(15), one O(17), one O(5), and one O(9) atom to form distorted TiO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-16°. In the second Ti site, Ti(2) is bonded to one O(10), one O(20), one O(21), one O(22), one O(24), and one O(8) atom to form distorted TiO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-15°. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(17), one O(21), one O(3), one O(4), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-16°. In the second Nb site, Nb(2) is bonded to one O(10), one O(12), one O(13), one O(15), one O(18), and one O(6) atom to form distorted NbO6 octahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-16°. In the third Nb site, Nb(3) is bonded to one O(11), one O(14), one O(16), one O(2), one O(20), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-12°. In the fourth Nb site, Nb(4) is bonded to one O(19), one O(22), one O(23), one O(24), one O(7), and one O(9) atom to form distorted NbO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-19°. There are eight inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 6-coordinate geometry to one O(10), one O(14), one O(18), one O(2), one O(22), and one O(8) atom. In the second Pb site, Pb(2) is bonded in a 5-coordinate geometry to one O(1), one O(16), one O(24), one O(7), and one O(9) atom. In the third Pb site, Pb(3) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(2), one O(20), and one O(6) atom. In the fourth Pb site, Pb(4) is bonded in a 6-coordinate geometry to one O(1), one O(16), one O(19), one O(20), one O(24), and one O(9) atom. In the fifth Pb site, Pb(5) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(21), one O(3), and one O(5) atom. In the sixth Pb site, Pb(6) is bonded in a 5-coordinate geometry to one O(13), one O(15), one O(23), one O(4), and one O(6) atom. In the seventh Pb site, Pb(7) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(17), one O(21), and one O(3) atom. In the eighth Pb site, Pb(8) is bonded in a 6-coordinate geometry to one O(13), one O(15), one O(18), one O(19), one O(23), and one O(4) atom. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(2), one Nb(1), one Pb(2), and one Pb(4) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Nb(3), one Pb(1), and one Pb(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Nb(1), one Pb(5), and one Pb(7) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Mg(1), one Nb(1), one Pb(6), and one Pb(8) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ti(1), one Nb(1), and one Pb(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Mg(1), one Nb(2), one Pb(3), and one Pb(6) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(2), one Nb(4), and one Pb(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ti(2), one Nb(3), and one Pb(1) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Ti(1), one Nb(4), one Pb(2), and one Pb(4) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Ti(2), one Nb(2), one Pb(1), and one Pb(3) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Ti(1), one Nb(3), one Pb(5), and one Pb(7) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Ti(1), one Nb(2), one Pb(5), and one Pb(7) atom. In the thirteenth O site, O(13) is bonded in a distorted see-saw-like geometry to one Mg(2), one Nb(2), one Pb(6), and one Pb(8) atom. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to one Mg(2), one Nb(3), one Pb(1), and one Pb(3) atom. In the fifteenth O site, O(15) is bonded in a 1-coordinate geometry to one Ti(1), one Nb(2), one Pb(6), and one Pb(8) atom. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to one Mg(2), one Nb(3), one Pb(2), and one Pb(4) atom. In the seventeenth O site, O(17) is bonded in a distorted T-shaped geometry to one Ti(1), one Nb(1), and one Pb(7) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Mg(1), one Nb(2), one Pb(1), and one Pb(8) atom. In the nineteenth O site, O(19) is bonded in a 3-coordinate geometry to one Mg(2), one Nb(4), one Pb(4), and one Pb(8) atom. In the twentieth O site, O(20) is bonded in a 2-coordinate geometry to one Ti(2), one Nb(3), one Pb(3), and one Pb(4) atom. In the twenty-first O site, O(21) is bonded in a 4-coordinate geometry to one Ti(2), one Nb(1), one Pb(5), and one Pb(7) atom. In the twenty-second O site, O(22) is bonded in a distorted linear geometry to one Ti(2), one Nb(4), and one Pb(1) atom. In the twenty-third O site, O(23) is bonded in a 2-coordinate geometry to one Mg(1), one Nb(4), one Pb(6), and one Pb(8) atom. In the twenty-fourth O site, O(24) is bonded in a 1-coordinate geometry to one Ti(2), one Nb(4), one Pb(2), and one Pb(4) atom. is represented by the CIF card [CIF]
data_MgTiNb2(PbO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.060
_cell_length_b   8.302
_cell_length_c   9.980
_cell_angle_alpha   113.708
_cell_angle_beta   113.745
_cell_angle_gamma   89.852
_symmetry_Int_Tables_number   1
_cell_volume   549.455
_cell_formula_units_Z   2
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  0.389  0.890  0.262  1.0
  Mg  Mg1  1  0.137  0.138  0.758  1.0
  Ti  Ti2  1  0.879  0.376  0.252  1.0
  Ti  Ti3  1  0.631  0.628  0.757  1.0
  Nb  Nb4  1  0.383  0.392  0.258  1.0
  Nb  Nb5  1  0.886  0.878  0.257  1.0
  Nb  Nb6  1  0.130  0.644  0.754  1.0
  Nb  Nb7  1  0.638  0.128  0.760  1.0
  Pb  Pb8  1  0.018  0.975  0.998  1.0
  Pb  Pb9  1  0.000  0.480  0.981  1.0
  Pb  Pb10  1  0.483  0.976  0.995  1.0
  Pb  Pb11  1  0.486  0.482  0.981  1.0
  Pb  Pb12  1  0.738  0.732  0.486  1.0
  Pb  Pb13  1  0.753  0.222  0.488  1.0
  Pb  Pb14  1  0.252  0.735  0.490  1.0
  Pb  Pb15  1  0.241  0.221  0.490  1.0
  O  O16  1  0.273  0.292  0.028  1.0
  O  O17  1  0.265  0.790  0.011  1.0
  O  O18  1  0.408  0.656  0.294  1.0
  O  O19  1  0.403  0.173  0.284  1.0
  O  O20  1  0.654  0.418  0.283  1.0
  O  O21  1  0.649  0.921  0.271  1.0
  O  O22  1  0.892  0.178  0.784  1.0
  O  O23  1  0.892  0.661  0.773  1.0
  O  O24  1  0.774  0.295  0.029  1.0
  O  O25  1  0.769  0.791  0.017  1.0
  O  O26  1  0.020  0.537  0.517  1.0
  O  O27  1  0.896  0.658  0.274  1.0
  O  O28  1  0.013  0.039  0.506  1.0
  O  O29  1  0.150  0.898  0.774  1.0
  O  O30  1  0.894  0.167  0.271  1.0
  O  O31  1  0.151  0.420  0.782  1.0
  O  O32  1  0.146  0.418  0.281  1.0
  O  O33  1  0.137  0.921  0.269  1.0
  O  O34  1  0.408  0.178  0.784  1.0
  O  O35  1  0.400  0.660  0.773  1.0
  O  O36  1  0.527  0.543  0.532  1.0
  O  O37  1  0.646  0.908  0.774  1.0
  O  O38  1  0.523  0.042  0.528  1.0
  O  O39  1  0.651  0.421  0.784  1.0
[/CIF]
.