The compound described by Tl4SiSe4 crystallizes in the monoclinic C2/c space group. There are five inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 4-coordinate geometry to two equivalent Se(1) and two equivalent Se(2) atoms. In the second Tl site, Tl(2) is bonded in a square co-planar geometry to two equivalent Se(3) and two equivalent Se(4) atoms. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. In the fourth Tl site, Tl(4) is bonded in a 1-coordinate geometry to one Se(3) and one Se(4) atom. In the fifth Tl site, Tl(5) is bonded in a 4-coordinate geometry to two equivalent Se(3) and two equivalent Se(4) atoms. Si(1) is bonded in a tetrahedral geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 1-coordinate geometry to one Tl(1), one Tl(3), and one Si(1) atom. In the second Se site, Se(2) is bonded in a 1-coordinate geometry to one Tl(1), one Tl(3), and one Si(1) atom. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to one Tl(2), one Tl(3), one Tl(4), two equivalent Tl(5), and one Si(1) atom. In the fourth Se site, Se(4) is bonded in a 6-coordinate geometry to one Tl(2), one Tl(3), one Tl(4), two equivalent Tl(5), and one Si(1) atom. is represented by the CIF card [CIF]
data_Tl4SiSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.002
_cell_length_b   7.002
_cell_length_c   25.104
_cell_angle_alpha   81.716
_cell_angle_beta   81.716
_cell_angle_gamma   63.737
_symmetry_Int_Tables_number   1
_cell_volume   1087.833
_cell_formula_units_Z   4
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
  Tl  Tl0  1  0.171  0.829  0.250  1.0
  Tl  Tl1  1  0.829  0.171  0.750  1.0
  Tl  Tl2  1  0.000  0.000  0.500  1.0
  Tl  Tl3  1  0.000  0.000  0.000  1.0
  Tl  Tl4  1  0.057  0.331  0.336  1.0
  Tl  Tl5  1  0.669  0.943  0.164  1.0
  Tl  Tl6  1  0.943  0.669  0.664  1.0
  Tl  Tl7  1  0.331  0.057  0.836  1.0
  Tl  Tl8  1  0.897  0.326  0.176  1.0
  Tl  Tl9  1  0.674  0.103  0.324  1.0
  Tl  Tl10  1  0.103  0.674  0.824  1.0
  Tl  Tl11  1  0.326  0.897  0.676  1.0
  Tl  Tl12  1  0.274  0.349  0.500  1.0
  Tl  Tl13  1  0.651  0.726  1.000  1.0
  Tl  Tl14  1  0.726  0.651  0.500  1.0
  Tl  Tl15  1  0.349  0.274  0.000  1.0
  Si  Si16  1  0.441  0.686  0.377  1.0
  Si  Si17  1  0.686  0.441  0.877  1.0
  Si  Si18  1  0.559  0.314  0.623  1.0
  Si  Si19  1  0.314  0.559  0.123  1.0
  Se  Se20  1  0.601  0.695  0.291  1.0
  Se  Se21  1  0.705  0.106  0.882  1.0
  Se  Se22  1  0.106  0.705  0.382  1.0
  Se  Se23  1  0.295  0.894  0.118  1.0
  Se  Se24  1  0.339  0.625  0.577  1.0
  Se  Se25  1  0.894  0.295  0.618  1.0
  Se  Se26  1  0.661  0.375  0.423  1.0
  Se  Se27  1  0.625  0.339  0.077  1.0
  Se  Se28  1  0.969  0.418  0.917  1.0
  Se  Se29  1  0.582  0.031  0.583  1.0
  Se  Se30  1  0.031  0.582  0.083  1.0
  Se  Se31  1  0.418  0.969  0.417  1.0
  Se  Se32  1  0.305  0.399  0.209  1.0
  Se  Se33  1  0.399  0.305  0.709  1.0
  Se  Se34  1  0.695  0.601  0.791  1.0
  Se  Se35  1  0.375  0.661  0.923  1.0
[/CIF]
.
The compound described by Tl4SiSe4 crystallizes in the monoclinic C2/c space group. There are five inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 4-coordinate geometry to two equivalent Se(1) and two equivalent Se(2) atoms. In the second Tl site, Tl(2) is bonded in a square co-planar geometry to two equivalent Se(3) and two equivalent Se(4) atoms. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. In the fourth Tl site, Tl(4) is bonded in a 1-coordinate geometry to one Se(3) and one Se(4) atom. In the fifth Tl site, Tl(5) is bonded in a 4-coordinate geometry to two equivalent Se(3) and two equivalent Se(4) atoms. Si(1) is bonded in a tetrahedral geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 1-coordinate geometry to one Tl(1), one Tl(3), and one Si(1) atom. In the second Se site, Se(2) is bonded in a 1-coordinate geometry to one Tl(1), one Tl(3), and one Si(1) atom. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to one Tl(2), one Tl(3), one Tl(4), two equivalent Tl(5), and one Si(1) atom. In the fourth Se site, Se(4) is bonded in a 6-coordinate geometry to one Tl(2), one Tl(3), one Tl(4), two equivalent Tl(5), and one Si(1) atom. is represented by the CIF card [CIF]
data_Tl4SiSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.002
_cell_length_b   7.002
_cell_length_c   25.104
_cell_angle_alpha   81.716
_cell_angle_beta   81.716
_cell_angle_gamma   63.737
_symmetry_Int_Tables_number   1
_cell_volume   1087.833
_cell_formula_units_Z   4
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
  Tl  Tl0  1  0.171  0.829  0.250  1.0
  Tl  Tl1  1  0.829  0.171  0.750  1.0
  Tl  Tl2  1  0.000  0.000  0.500  1.0
  Tl  Tl3  1  0.000  0.000  0.000  1.0
  Tl  Tl4  1  0.057  0.331  0.336  1.0
  Tl  Tl5  1  0.669  0.943  0.164  1.0
  Tl  Tl6  1  0.943  0.669  0.664  1.0
  Tl  Tl7  1  0.331  0.057  0.836  1.0
  Tl  Tl8  1  0.897  0.326  0.176  1.0
  Tl  Tl9  1  0.674  0.103  0.324  1.0
  Tl  Tl10  1  0.103  0.674  0.824  1.0
  Tl  Tl11  1  0.326  0.897  0.676  1.0
  Tl  Tl12  1  0.274  0.349  0.500  1.0
  Tl  Tl13  1  0.651  0.726  1.000  1.0
  Tl  Tl14  1  0.726  0.651  0.500  1.0
  Tl  Tl15  1  0.349  0.274  0.000  1.0
  Si  Si16  1  0.441  0.686  0.377  1.0
  Si  Si17  1  0.686  0.441  0.877  1.0
  Si  Si18  1  0.559  0.314  0.623  1.0
  Si  Si19  1  0.314  0.559  0.123  1.0
  Se  Se20  1  0.601  0.695  0.291  1.0
  Se  Se21  1  0.705  0.106  0.882  1.0
  Se  Se22  1  0.106  0.705  0.382  1.0
  Se  Se23  1  0.295  0.894  0.118  1.0
  Se  Se24  1  0.339  0.625  0.577  1.0
  Se  Se25  1  0.894  0.295  0.618  1.0
  Se  Se26  1  0.661  0.375  0.423  1.0
  Se  Se27  1  0.625  0.339  0.077  1.0
  Se  Se28  1  0.969  0.418  0.917  1.0
  Se  Se29  1  0.582  0.031  0.583  1.0
  Se  Se30  1  0.031  0.582  0.083  1.0
  Se  Se31  1  0.418  0.969  0.417  1.0
  Se  Se32  1  0.305  0.399  0.209  1.0
  Se  Se33  1  0.399  0.305  0.709  1.0
  Se  Se34  1  0.695  0.601  0.791  1.0
  Se  Se35  1  0.375  0.661  0.923  1.0
[/CIF]
.