The material structure described by La2PbSi2Se8 crystallizes in the monoclinic Cc space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), one Se(8), and two equivalent Se(6) atoms. In the second La site, La(2) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), one Se(5), one Se(8), two equivalent Se(4), and two equivalent Se(7) atoms. Pb(1) is bonded in a 5-coordinate geometry to one Se(1), one Se(7), one Se(8), and two equivalent Se(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one Se(1), one Se(3), one Se(4), and one Se(5) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one Se(2), one Se(6), one Se(7), and one Se(8) atom. There are eight inequivalent Se sites. In the first Se site, Se(8) is bonded in a 4-coordinate geometry to one La(1), one La(2), one Pb(1), and one Si(2) atom. In the second Se site, Se(1) is bonded in a 3-coordinate geometry to one La(1), one La(2), one Pb(1), and one Si(1) atom. In the third Se site, Se(2) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Si(2) atom. In the fourth Se site, Se(3) is bonded in a distorted single-bond geometry to one La(1), two equivalent Pb(1), and one Si(1) atom. In the fifth Se site, Se(4) is bonded to one La(1), two equivalent La(2), and one Si(1) atom to form distorted SeLa3Si trigonal pyramids that share corners with two equivalent Se(7)La2SiPb trigonal pyramids, corners with two equivalent Se(4)La3Si trigonal pyramids, and  an edgeedge with one Se(7)La2SiPb trigonal pyramid. In the sixth Se site, Se(5) is bonded in a distorted T-shaped geometry to one La(1), one La(2), and one Si(1) atom. In the seventh Se site, Se(6) is bonded in a T-shaped geometry to two equivalent La(1) and one Si(2) atom. In the eighth Se site, Se(7) is bonded to two equivalent La(2), one Pb(1), and one Si(2) atom to form distorted SeLa2SiPb trigonal pyramids that share corners with two equivalent Se(7)La2SiPb trigonal pyramids, corners with two equivalent Se(4)La3Si trigonal pyramids, and  an edgeedge with one Se(4)La3Si trigonal pyramid. is represented by the CIF card [CIF]
data_La2Si2PbSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.551
_cell_length_b   9.551
_cell_length_c   10.824
_cell_angle_alpha   65.301
_cell_angle_beta   65.301
_cell_angle_gamma   59.941
_symmetry_Int_Tables_number   1
_cell_volume   748.642
_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
  La  La0  1  0.248  0.440  0.252  1.0
  La  La1  1  0.944  0.059  0.246  1.0
  La  La2  1  0.440  0.248  0.752  1.0
  La  La3  1  0.059  0.944  0.746  1.0
  Si  Si4  1  0.331  0.849  0.978  1.0
  Si  Si5  1  0.849  0.331  0.478  1.0
  Si  Si6  1  0.653  0.166  0.022  1.0
  Si  Si7  1  0.166  0.653  0.522  1.0
  Pb  Pb8  1  0.570  0.748  0.250  1.0
  Pb  Pb9  1  0.748  0.570  0.750  1.0
  Se  Se10  1  0.407  0.931  0.737  1.0
  Se  Se11  1  0.931  0.407  0.237  1.0
  Se  Se12  1  0.587  0.095  0.263  1.0
  Se  Se13  1  0.095  0.587  0.763  1.0
  Se  Se14  1  0.530  0.610  0.074  1.0
  Se  Se15  1  0.097  0.789  0.056  1.0
  Se  Se16  1  0.273  0.070  0.052  1.0
  Se  Se17  1  0.789  0.097  0.556  1.0
  Se  Se18  1  0.610  0.530  0.574  1.0
  Se  Se19  1  0.070  0.273  0.552  1.0
  Se  Se20  1  0.427  0.396  0.953  1.0
  Se  Se21  1  0.890  0.221  0.932  1.0
  Se  Se22  1  0.711  0.957  0.933  1.0
  Se  Se23  1  0.221  0.890  0.432  1.0
  Se  Se24  1  0.396  0.427  0.453  1.0
  Se  Se25  1  0.957  0.711  0.433  1.0
[/CIF]
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The material structure described by La2PbSi2Se8 crystallizes in the monoclinic Cc space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), one Se(8), and two equivalent Se(6) atoms. In the second La site, La(2) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), one Se(5), one Se(8), two equivalent Se(4), and two equivalent Se(7) atoms. Pb(1) is bonded in a 5-coordinate geometry to one Se(1), one Se(7), one Se(8), and two equivalent Se(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one Se(1), one Se(3), one Se(4), and one Se(5) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one Se(2), one Se(6), one Se(7), and one Se(8) atom. There are eight inequivalent Se sites. In the first Se site, Se(8) is bonded in a 4-coordinate geometry to one La(1), one La(2), one Pb(1), and one Si(2) atom. In the second Se site, Se(1) is bonded in a 3-coordinate geometry to one La(1), one La(2), one Pb(1), and one Si(1) atom. In the third Se site, Se(2) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Si(2) atom. In the fourth Se site, Se(3) is bonded in a distorted single-bond geometry to one La(1), two equivalent Pb(1), and one Si(1) atom. In the fifth Se site, Se(4) is bonded to one La(1), two equivalent La(2), and one Si(1) atom to form distorted SeLa3Si trigonal pyramids that share corners with two equivalent Se(7)La2SiPb trigonal pyramids, corners with two equivalent Se(4)La3Si trigonal pyramids, and  an edgeedge with one Se(7)La2SiPb trigonal pyramid. In the sixth Se site, Se(5) is bonded in a distorted T-shaped geometry to one La(1), one La(2), and one Si(1) atom. In the seventh Se site, Se(6) is bonded in a T-shaped geometry to two equivalent La(1) and one Si(2) atom. In the eighth Se site, Se(7) is bonded to two equivalent La(2), one Pb(1), and one Si(2) atom to form distorted SeLa2SiPb trigonal pyramids that share corners with two equivalent Se(7)La2SiPb trigonal pyramids, corners with two equivalent Se(4)La3Si trigonal pyramids, and  an edgeedge with one Se(4)La3Si trigonal pyramid. is represented by the CIF card [CIF]
data_La2Si2PbSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.551
_cell_length_b   9.551
_cell_length_c   10.824
_cell_angle_alpha   65.301
_cell_angle_beta   65.301
_cell_angle_gamma   59.941
_symmetry_Int_Tables_number   1
_cell_volume   748.642
_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
  La  La0  1  0.248  0.440  0.252  1.0
  La  La1  1  0.944  0.059  0.246  1.0
  La  La2  1  0.440  0.248  0.752  1.0
  La  La3  1  0.059  0.944  0.746  1.0
  Si  Si4  1  0.331  0.849  0.978  1.0
  Si  Si5  1  0.849  0.331  0.478  1.0
  Si  Si6  1  0.653  0.166  0.022  1.0
  Si  Si7  1  0.166  0.653  0.522  1.0
  Pb  Pb8  1  0.570  0.748  0.250  1.0
  Pb  Pb9  1  0.748  0.570  0.750  1.0
  Se  Se10  1  0.407  0.931  0.737  1.0
  Se  Se11  1  0.931  0.407  0.237  1.0
  Se  Se12  1  0.587  0.095  0.263  1.0
  Se  Se13  1  0.095  0.587  0.763  1.0
  Se  Se14  1  0.530  0.610  0.074  1.0
  Se  Se15  1  0.097  0.789  0.056  1.0
  Se  Se16  1  0.273  0.070  0.052  1.0
  Se  Se17  1  0.789  0.097  0.556  1.0
  Se  Se18  1  0.610  0.530  0.574  1.0
  Se  Se19  1  0.070  0.273  0.552  1.0
  Se  Se20  1  0.427  0.396  0.953  1.0
  Se  Se21  1  0.890  0.221  0.932  1.0
  Se  Se22  1  0.711  0.957  0.933  1.0
  Se  Se23  1  0.221  0.890  0.432  1.0
  Se  Se24  1  0.396  0.427  0.453  1.0
  Se  Se25  1  0.957  0.711  0.433  1.0
[/CIF]
.