The material structure described by Pb4Bi12O21 crystallizes in the triclinic P-1 space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted T-shaped geometry to one O(11), one O(2), and one O(8) atom. In the second Pb site, Pb(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(5), and one O(8) atom. There are six inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to one O(10), one O(6), one O(7), and one O(9) atom. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(10), one O(3), one O(4), one O(6), and one O(7) atom. In the third Bi site, Bi(3) is bonded to one O(1), one O(2), one O(5), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing BiO5 square pyramids. In the fourth Bi site, Bi(4) is bonded to one O(10), one O(4), one O(9), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing BiO5 square pyramids. In the fifth Bi site, Bi(5) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the sixth Bi site, Bi(6) is bonded to one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form distorted corner-sharing BiO5 square pyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Pb(2), one Bi(3), and one Bi(5) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Pb(1), one Bi(3), and one Bi(5) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Pb(2), one Bi(2), one Bi(5), and one Bi(6) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Bi(2), one Bi(4), and one Bi(6) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Pb(2), one Bi(3), and one Bi(6) atom. In the sixth O site, O(6) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(4) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the seventh O site, O(7) is bonded to one Bi(1), one Bi(2), one Bi(5), and one Bi(6) atom to form distorted corner-sharing OBi4 trigonal pyramids. In the eighth O site, O(8) is bonded to one Pb(1), one Pb(2), and two equivalent Bi(3) atoms to form edge-sharing OBi2Pb2 tetrahedra. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(4), and one Bi(6) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Bi(1), one Bi(2), and one Bi(4) atom. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent Pb(1) atoms. is represented by the CIF file [CIF]
data_Bi12Pb4O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.288
_cell_length_b   7.648
_cell_length_c   14.297
_cell_angle_alpha   93.352
_cell_angle_beta   97.500
_cell_angle_gamma   116.458
_symmetry_Int_Tables_number   1
_cell_volume   701.159
_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
  Bi  Bi0  1  0.778  0.007  0.300  1.0
  Bi  Bi1  1  0.222  0.993  0.700  1.0
  Bi  Bi2  1  0.508  0.802  0.572  1.0
  Bi  Bi3  1  0.492  0.198  0.428  1.0
  Bi  Bi4  1  0.516  0.740  0.044  1.0
  Bi  Bi5  1  0.484  0.260  0.956  1.0
  Bi  Bi6  1  0.066  0.271  0.524  1.0
  Bi  Bi7  1  0.934  0.729  0.476  1.0
  Bi  Bi8  1  0.259  0.005  0.172  1.0
  Bi  Bi9  1  0.741  0.995  0.828  1.0
  Bi  Bi10  1  0.346  0.566  0.310  1.0
  Bi  Bi11  1  0.654  0.434  0.690  1.0
  Pb  Pb12  1  0.027  0.292  0.057  1.0
  Pb  Pb13  1  0.973  0.708  0.943  1.0
  Pb  Pb14  1  0.744  0.486  0.204  1.0
  Pb  Pb15  1  0.256  0.514  0.796  1.0
  O  O16  1  0.457  0.820  0.877  1.0
  O  O17  1  0.543  0.180  0.123  1.0
  O  O18  1  0.222  0.756  0.074  1.0
  O  O19  1  0.778  0.244  0.926  1.0
  O  O20  1  0.536  0.658  0.694  1.0
  O  O21  1  0.464  0.342  0.306  1.0
  O  O22  1  0.296  0.525  0.470  1.0
  O  O23  1  0.704  0.475  0.530  1.0
  O  O24  1  0.518  0.619  0.184  1.0
  O  O25  1  0.482  0.381  0.816  1.0
  O  O26  1  0.076  0.077  0.411  1.0
  O  O27  1  0.924  0.923  0.589  1.0
  O  O28  1  0.430  0.931  0.293  1.0
  O  O29  1  0.570  0.069  0.707  1.0
  O  O30  1  0.711  0.547  0.032  1.0
  O  O31  1  0.289  0.453  0.968  1.0
  O  O32  1  0.658  0.770  0.391  1.0
  O  O33  1  0.342  0.230  0.609  1.0
  O  O34  1  0.194  0.753  0.602  1.0
  O  O35  1  0.806  0.247  0.398  1.0
  O  O36  1  0.000  0.000  0.000  1.0
[/CIF]
.
The material structure described by Pb4Bi12O21 crystallizes in the triclinic P-1 space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted T-shaped geometry to one O(11), one O(2), and one O(8) atom. In the second Pb site, Pb(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(5), and one O(8) atom. There are six inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to one O(10), one O(6), one O(7), and one O(9) atom. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(10), one O(3), one O(4), one O(6), and one O(7) atom. In the third Bi site, Bi(3) is bonded to one O(1), one O(2), one O(5), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing BiO5 square pyramids. In the fourth Bi site, Bi(4) is bonded to one O(10), one O(4), one O(9), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing BiO5 square pyramids. In the fifth Bi site, Bi(5) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the sixth Bi site, Bi(6) is bonded to one O(3), one O(4), one O(5), one O(7), and one O(9) atom to form distorted corner-sharing BiO5 square pyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Pb(2), one Bi(3), and one Bi(5) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Pb(1), one Bi(3), and one Bi(5) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Pb(2), one Bi(2), one Bi(5), and one Bi(6) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Bi(2), one Bi(4), and one Bi(6) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Pb(2), one Bi(3), and one Bi(6) atom. In the sixth O site, O(6) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(4) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the seventh O site, O(7) is bonded to one Bi(1), one Bi(2), one Bi(5), and one Bi(6) atom to form distorted corner-sharing OBi4 trigonal pyramids. In the eighth O site, O(8) is bonded to one Pb(1), one Pb(2), and two equivalent Bi(3) atoms to form edge-sharing OBi2Pb2 tetrahedra. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(4), and one Bi(6) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Bi(1), one Bi(2), and one Bi(4) atom. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent Pb(1) atoms. is represented by the CIF file [CIF]
data_Bi12Pb4O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.288
_cell_length_b   7.648
_cell_length_c   14.297
_cell_angle_alpha   93.352
_cell_angle_beta   97.500
_cell_angle_gamma   116.458
_symmetry_Int_Tables_number   1
_cell_volume   701.159
_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
  Bi  Bi0  1  0.778  0.007  0.300  1.0
  Bi  Bi1  1  0.222  0.993  0.700  1.0
  Bi  Bi2  1  0.508  0.802  0.572  1.0
  Bi  Bi3  1  0.492  0.198  0.428  1.0
  Bi  Bi4  1  0.516  0.740  0.044  1.0
  Bi  Bi5  1  0.484  0.260  0.956  1.0
  Bi  Bi6  1  0.066  0.271  0.524  1.0
  Bi  Bi7  1  0.934  0.729  0.476  1.0
  Bi  Bi8  1  0.259  0.005  0.172  1.0
  Bi  Bi9  1  0.741  0.995  0.828  1.0
  Bi  Bi10  1  0.346  0.566  0.310  1.0
  Bi  Bi11  1  0.654  0.434  0.690  1.0
  Pb  Pb12  1  0.027  0.292  0.057  1.0
  Pb  Pb13  1  0.973  0.708  0.943  1.0
  Pb  Pb14  1  0.744  0.486  0.204  1.0
  Pb  Pb15  1  0.256  0.514  0.796  1.0
  O  O16  1  0.457  0.820  0.877  1.0
  O  O17  1  0.543  0.180  0.123  1.0
  O  O18  1  0.222  0.756  0.074  1.0
  O  O19  1  0.778  0.244  0.926  1.0
  O  O20  1  0.536  0.658  0.694  1.0
  O  O21  1  0.464  0.342  0.306  1.0
  O  O22  1  0.296  0.525  0.470  1.0
  O  O23  1  0.704  0.475  0.530  1.0
  O  O24  1  0.518  0.619  0.184  1.0
  O  O25  1  0.482  0.381  0.816  1.0
  O  O26  1  0.076  0.077  0.411  1.0
  O  O27  1  0.924  0.923  0.589  1.0
  O  O28  1  0.430  0.931  0.293  1.0
  O  O29  1  0.570  0.069  0.707  1.0
  O  O30  1  0.711  0.547  0.032  1.0
  O  O31  1  0.289  0.453  0.968  1.0
  O  O32  1  0.658  0.770  0.391  1.0
  O  O33  1  0.342  0.230  0.609  1.0
  O  O34  1  0.194  0.753  0.602  1.0
  O  O35  1  0.806  0.247  0.398  1.0
  O  O36  1  0.000  0.000  0.000  1.0
[/CIF]
.