The compound described by Nb12PbSe16 crystallizes in the triclinic P-1 space group. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one Se(2), one Se(5), one Se(7), one Se(8), and two equivalent Se(6) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one Se(1), one Se(6), one Se(7), one Se(8), and two equivalent Se(5) atoms. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to one Se(1), one Se(4), one Se(7), one Se(8), and two equivalent Se(2) atoms. In the fourth Nb site, Nb(4) is bonded to one Se(2), one Se(3), one Se(7), one Se(8), and two equivalent Se(1) atoms to form distorted edge-sharing NbSe6 octahedra. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to one Se(3), one Se(6), one Se(7), one Se(8), and two equivalent Se(4) atoms. In the sixth Nb site, Nb(6) is bonded in a 6-coordinate geometry to one Se(4), one Se(5), one Se(7), one Se(8), and two equivalent Se(3) atoms. Pb(1) is bonded in a distorted hexagonal planar geometry to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(5) atoms. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(3), two equivalent Nb(4), and one Pb(1) atom. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(4), and two equivalent Nb(3) atoms. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one Nb(4), one Nb(5), and two equivalent Nb(6) atoms. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to one Nb(3), one Nb(6), two equivalent Nb(5), and one Pb(1) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(6), two equivalent Nb(2), and one Pb(1) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(5), and two equivalent Nb(1) atoms. In the seventh Se site, Se(7) is bonded to one Nb(1), one Nb(2), one Nb(3), one Nb(4), one Nb(5), and one Nb(6) atom to form distorted face-sharing SeNb6 pentagonal pyramids. In the eighth Se site, Se(8) is bonded to one Nb(1), one Nb(2), one Nb(3), one Nb(4), one Nb(5), and one Nb(6) atom to form distorted face-sharing SeNb6 pentagonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb12PbSe16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.082
_cell_length_b   10.058
_cell_length_c   10.661
_cell_angle_alpha   118.125
_cell_angle_beta   109.363
_cell_angle_gamma   90.008
_symmetry_Int_Tables_number   1
_cell_volume   620.540
_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
  Nb  Nb0  1  0.929  0.487  0.107  1.0
  Nb  Nb1  1  0.429  0.487  0.107  1.0
  Nb  Nb2  1  0.131  0.620  0.513  1.0
  Nb  Nb3  1  0.633  0.623  0.513  1.0
  Nb  Nb4  1  0.067  0.893  0.379  1.0
  Nb  Nb5  1  0.564  0.894  0.381  1.0
  Nb  Nb6  1  0.571  0.513  0.893  1.0
  Nb  Nb7  1  0.071  0.513  0.893  1.0
  Nb  Nb8  1  0.367  0.377  0.487  1.0
  Nb  Nb9  1  0.869  0.380  0.487  1.0
  Nb  Nb10  1  0.436  0.106  0.619  1.0
  Nb  Nb11  1  0.933  0.107  0.621  1.0
  Pb  Pb12  1  0.500  0.000  0.000  1.0
  Se  Se13  1  0.513  0.336  0.278  1.0
  Se  Se14  1  0.015  0.338  0.280  1.0
  Se  Se15  1  0.706  0.941  0.662  1.0
  Se  Se16  1  0.205  0.943  0.664  1.0
  Se  Se17  1  0.402  0.722  0.058  1.0
  Se  Se18  1  0.905  0.721  0.059  1.0
  Se  Se19  1  0.985  0.662  0.720  1.0
  Se  Se20  1  0.487  0.664  0.722  1.0
  Se  Se21  1  0.795  0.057  0.336  1.0
  Se  Se22  1  0.294  0.059  0.338  1.0
  Se  Se23  1  0.095  0.279  0.941  1.0
  Se  Se24  1  0.598  0.278  0.942  1.0
  Se  Se25  1  0.709  0.334  0.666  1.0
  Se  Se26  1  0.208  0.333  0.666  1.0
  Se  Se27  1  0.792  0.667  0.334  1.0
  Se  Se28  1  0.291  0.666  0.334  1.0
[/CIF]
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The compound described by Nb12PbSe16 crystallizes in the triclinic P-1 space group. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one Se(2), one Se(5), one Se(7), one Se(8), and two equivalent Se(6) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one Se(1), one Se(6), one Se(7), one Se(8), and two equivalent Se(5) atoms. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to one Se(1), one Se(4), one Se(7), one Se(8), and two equivalent Se(2) atoms. In the fourth Nb site, Nb(4) is bonded to one Se(2), one Se(3), one Se(7), one Se(8), and two equivalent Se(1) atoms to form distorted edge-sharing NbSe6 octahedra. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to one Se(3), one Se(6), one Se(7), one Se(8), and two equivalent Se(4) atoms. In the sixth Nb site, Nb(6) is bonded in a 6-coordinate geometry to one Se(4), one Se(5), one Se(7), one Se(8), and two equivalent Se(3) atoms. Pb(1) is bonded in a distorted hexagonal planar geometry to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(5) atoms. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(3), two equivalent Nb(4), and one Pb(1) atom. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(4), and two equivalent Nb(3) atoms. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one Nb(4), one Nb(5), and two equivalent Nb(6) atoms. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to one Nb(3), one Nb(6), two equivalent Nb(5), and one Pb(1) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(6), two equivalent Nb(2), and one Pb(1) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(5), and two equivalent Nb(1) atoms. In the seventh Se site, Se(7) is bonded to one Nb(1), one Nb(2), one Nb(3), one Nb(4), one Nb(5), and one Nb(6) atom to form distorted face-sharing SeNb6 pentagonal pyramids. In the eighth Se site, Se(8) is bonded to one Nb(1), one Nb(2), one Nb(3), one Nb(4), one Nb(5), and one Nb(6) atom to form distorted face-sharing SeNb6 pentagonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb12PbSe16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.082
_cell_length_b   10.058
_cell_length_c   10.661
_cell_angle_alpha   118.125
_cell_angle_beta   109.363
_cell_angle_gamma   90.008
_symmetry_Int_Tables_number   1
_cell_volume   620.540
_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
  Nb  Nb0  1  0.929  0.487  0.107  1.0
  Nb  Nb1  1  0.429  0.487  0.107  1.0
  Nb  Nb2  1  0.131  0.620  0.513  1.0
  Nb  Nb3  1  0.633  0.623  0.513  1.0
  Nb  Nb4  1  0.067  0.893  0.379  1.0
  Nb  Nb5  1  0.564  0.894  0.381  1.0
  Nb  Nb6  1  0.571  0.513  0.893  1.0
  Nb  Nb7  1  0.071  0.513  0.893  1.0
  Nb  Nb8  1  0.367  0.377  0.487  1.0
  Nb  Nb9  1  0.869  0.380  0.487  1.0
  Nb  Nb10  1  0.436  0.106  0.619  1.0
  Nb  Nb11  1  0.933  0.107  0.621  1.0
  Pb  Pb12  1  0.500  0.000  0.000  1.0
  Se  Se13  1  0.513  0.336  0.278  1.0
  Se  Se14  1  0.015  0.338  0.280  1.0
  Se  Se15  1  0.706  0.941  0.662  1.0
  Se  Se16  1  0.205  0.943  0.664  1.0
  Se  Se17  1  0.402  0.722  0.058  1.0
  Se  Se18  1  0.905  0.721  0.059  1.0
  Se  Se19  1  0.985  0.662  0.720  1.0
  Se  Se20  1  0.487  0.664  0.722  1.0
  Se  Se21  1  0.795  0.057  0.336  1.0
  Se  Se22  1  0.294  0.059  0.338  1.0
  Se  Se23  1  0.095  0.279  0.941  1.0
  Se  Se24  1  0.598  0.278  0.942  1.0
  Se  Se25  1  0.709  0.334  0.666  1.0
  Se  Se26  1  0.208  0.333  0.666  1.0
  Se  Se27  1  0.792  0.667  0.334  1.0
  Se  Se28  1  0.291  0.666  0.334  1.0
[/CIF]
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