The compound described by PbBi2Nb2O9 crystallizes in the orthorhombic Cmc2_1 space group. Nb(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 20-22°. Pb(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(5), and four equivalent O(2) atoms. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Nb(1) and two equivalent Pb(1) atoms. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Nb(1) and one Pb(1) atom. In the fourth O site, O(4) is bonded to four equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to two equivalent Nb(1) and two equivalent Pb(1) atoms. is represented by the CIF file [CIF]
data_Nb2Bi2PbO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.995
_cell_length_b   12.995
_cell_length_c   5.700
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   154.855
_symmetry_Int_Tables_number   1
_cell_volume   409.062
_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
  Nb  Nb0  1  0.836  0.666  0.232  1.0
  Nb  Nb1  1  0.666  0.836  0.232  1.0
  Nb  Nb2  1  0.334  0.164  0.732  1.0
  Nb  Nb3  1  0.164  0.334  0.732  1.0
  Bi  Bi4  1  0.084  0.485  0.311  1.0
  Bi  Bi5  1  0.515  0.916  0.811  1.0
  Bi  Bi6  1  0.916  0.515  0.811  1.0
  Bi  Bi7  1  0.485  0.084  0.311  1.0
  Pb  Pb8  1  0.754  0.754  0.754  1.0
  Pb  Pb9  1  0.246  0.246  0.254  1.0
  O  O10  1  0.836  0.521  0.192  1.0
  O  O11  1  0.454  0.594  0.472  1.0
  O  O12  1  0.881  0.057  0.921  1.0
  O  O13  1  0.164  0.479  0.692  1.0
  O  O14  1  0.769  0.266  0.520  1.0
  O  O15  1  0.201  0.201  0.684  1.0
  O  O16  1  0.479  0.164  0.692  1.0
  O  O17  1  0.943  0.119  0.421  1.0
  O  O18  1  0.594  0.454  0.472  1.0
  O  O19  1  0.231  0.734  0.020  1.0
  O  O20  1  0.057  0.881  0.921  1.0
  O  O21  1  0.734  0.231  0.020  1.0
  O  O22  1  0.521  0.836  0.192  1.0
  O  O23  1  0.266  0.769  0.520  1.0
  O  O24  1  0.119  0.943  0.421  1.0
  O  O25  1  0.546  0.406  0.972  1.0
  O  O26  1  0.799  0.799  0.184  1.0
  O  O27  1  0.406  0.546  0.972  1.0
[/CIF]
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The compound described by PbBi2Nb2O9 crystallizes in the orthorhombic Cmc2_1 space group. Nb(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 20-22°. Pb(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(5), and four equivalent O(2) atoms. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Nb(1) and two equivalent Pb(1) atoms. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Nb(1) and one Pb(1) atom. In the fourth O site, O(4) is bonded to four equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to two equivalent Nb(1) and two equivalent Pb(1) atoms. is represented by the CIF file [CIF]
data_Nb2Bi2PbO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.995
_cell_length_b   12.995
_cell_length_c   5.700
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   154.855
_symmetry_Int_Tables_number   1
_cell_volume   409.062
_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
  Nb  Nb0  1  0.836  0.666  0.232  1.0
  Nb  Nb1  1  0.666  0.836  0.232  1.0
  Nb  Nb2  1  0.334  0.164  0.732  1.0
  Nb  Nb3  1  0.164  0.334  0.732  1.0
  Bi  Bi4  1  0.084  0.485  0.311  1.0
  Bi  Bi5  1  0.515  0.916  0.811  1.0
  Bi  Bi6  1  0.916  0.515  0.811  1.0
  Bi  Bi7  1  0.485  0.084  0.311  1.0
  Pb  Pb8  1  0.754  0.754  0.754  1.0
  Pb  Pb9  1  0.246  0.246  0.254  1.0
  O  O10  1  0.836  0.521  0.192  1.0
  O  O11  1  0.454  0.594  0.472  1.0
  O  O12  1  0.881  0.057  0.921  1.0
  O  O13  1  0.164  0.479  0.692  1.0
  O  O14  1  0.769  0.266  0.520  1.0
  O  O15  1  0.201  0.201  0.684  1.0
  O  O16  1  0.479  0.164  0.692  1.0
  O  O17  1  0.943  0.119  0.421  1.0
  O  O18  1  0.594  0.454  0.472  1.0
  O  O19  1  0.231  0.734  0.020  1.0
  O  O20  1  0.057  0.881  0.921  1.0
  O  O21  1  0.734  0.231  0.020  1.0
  O  O22  1  0.521  0.836  0.192  1.0
  O  O23  1  0.266  0.769  0.520  1.0
  O  O24  1  0.119  0.943  0.421  1.0
  O  O25  1  0.546  0.406  0.972  1.0
  O  O26  1  0.799  0.799  0.184  1.0
  O  O27  1  0.406  0.546  0.972  1.0
[/CIF]
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