The compound described by Ta2Tl4Se11 crystallizes in the triclinic P-1 space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one Se(1), one Se(10), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. In the second Ta site, Ta(2) is bonded to one Se(10), one Se(11), one Se(3), one Se(4), one Se(7), one Se(8), and one Se(9) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 2-coordinate geometry to one Se(1) and one Se(4) atom. In the second Tl site, Tl(2) is bonded in a 5-coordinate geometry to one Se(10), one Se(4), one Se(5), and two equivalent Se(11) atoms. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to one Se(2), one Se(5), and two equivalent Se(1) atoms. In the fourth Tl site, Tl(4) is bonded in a 4-coordinate geometry to one Se(7), one Se(9), and two equivalent Se(11) atoms. There are eleven inequivalent Se sites. In the first Se site, Se(11) is bonded in a 5-coordinate geometry to one Ta(2), two equivalent Tl(2), and two equivalent Tl(4) atoms. In the second Se site, Se(1) is bonded in a 4-coordinate geometry to one Ta(1), one Tl(1), and two equivalent Tl(3) atoms. In the third Se site, Se(2) is bonded in a distorted single-bond geometry to one Ta(1), one Tl(3), and one Se(3) atom. In the fourth Se site, Se(3) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(2), and one Se(2) atom. In the fifth Se site, Se(4) is bonded in a distorted see-saw-like geometry to one Ta(1), one Ta(2), one Tl(1), and one Tl(2) atom. In the sixth Se site, Se(5) is bonded in a 4-coordinate geometry to one Ta(1), one Tl(2), one Tl(3), and one Se(6) atom. In the seventh Se site, Se(6) is bonded in a distorted single-bond geometry to one Ta(1) and one Se(5) atom. In the eighth Se site, Se(7) is bonded in a distorted single-bond geometry to one Ta(2), one Tl(4), and one Se(10) atom. In the ninth Se site, Se(8) is bonded in a distorted single-bond geometry to one Ta(2) and one Se(9) atom. In the tenth Se site, Se(9) is bonded in a distorted single-bond geometry to one Ta(2), one Tl(4), and one Se(8) atom. In the eleventh Se site, Se(10) is bonded in a 4-coordinate geometry to one Ta(1), one Ta(2), one Tl(2), and one Se(7) atom. is represented by the CIF file [CIF]
data_Ta2Tl4Se11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.152
_cell_length_b   9.296
_cell_length_c   13.971
_cell_angle_alpha   107.415
_cell_angle_beta   89.331
_cell_angle_gamma   94.230
_symmetry_Int_Tables_number   1
_cell_volume   1007.343
_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
  Ta  Ta0  1  0.663  0.109  0.811  1.0
  Ta  Ta1  1  0.337  0.891  0.189  1.0
  Ta  Ta2  1  0.876  0.367  0.697  1.0
  Ta  Ta3  1  0.124  0.633  0.303  1.0
  Tl  Tl4  1  0.947  0.761  0.018  1.0
  Tl  Tl5  1  0.053  0.239  0.982  1.0
  Tl  Tl6  1  0.788  0.976  0.425  1.0
  Tl  Tl7  1  0.212  0.024  0.575  1.0
  Tl  Tl8  1  0.495  0.275  0.110  1.0
  Tl  Tl9  1  0.505  0.725  0.890  1.0
  Tl  Tl10  1  0.763  0.414  0.418  1.0
  Tl  Tl11  1  0.237  0.586  0.582  1.0
  Se  Se12  1  0.730  0.039  0.959  1.0
  Se  Se13  1  0.270  0.961  0.041  1.0
  Se  Se14  1  0.543  0.690  0.119  1.0
  Se  Se15  1  0.457  0.310  0.881  1.0
  Se  Se16  1  0.737  0.403  0.889  1.0
  Se  Se17  1  0.263  0.597  0.111  1.0
  Se  Se18  1  0.968  0.133  0.750  1.0
  Se  Se19  1  0.032  0.867  0.250  1.0
  Se  Se20  1  0.598  0.076  0.247  1.0
  Se  Se21  1  0.402  0.924  0.753  1.0
  Se  Se22  1  0.651  0.858  0.667  1.0
  Se  Se23  1  0.349  0.142  0.333  1.0
  Se  Se24  1  0.601  0.442  0.648  1.0
  Se  Se25  1  0.399  0.558  0.352  1.0
  Se  Se26  1  0.884  0.492  0.185  1.0
  Se  Se27  1  0.116  0.508  0.815  1.0
  Se  Se28  1  0.946  0.656  0.751  1.0
  Se  Se29  1  0.054  0.344  0.249  1.0
  Se  Se30  1  0.611  0.180  0.628  1.0
  Se  Se31  1  0.389  0.820  0.372  1.0
  Se  Se32  1  0.983  0.710  0.465  1.0
  Se  Se33  1  0.017  0.290  0.535  1.0
[/CIF]
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The compound described by Ta2Tl4Se11 crystallizes in the triclinic P-1 space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one Se(1), one Se(10), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. In the second Ta site, Ta(2) is bonded to one Se(10), one Se(11), one Se(3), one Se(4), one Se(7), one Se(8), and one Se(9) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 2-coordinate geometry to one Se(1) and one Se(4) atom. In the second Tl site, Tl(2) is bonded in a 5-coordinate geometry to one Se(10), one Se(4), one Se(5), and two equivalent Se(11) atoms. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to one Se(2), one Se(5), and two equivalent Se(1) atoms. In the fourth Tl site, Tl(4) is bonded in a 4-coordinate geometry to one Se(7), one Se(9), and two equivalent Se(11) atoms. There are eleven inequivalent Se sites. In the first Se site, Se(11) is bonded in a 5-coordinate geometry to one Ta(2), two equivalent Tl(2), and two equivalent Tl(4) atoms. In the second Se site, Se(1) is bonded in a 4-coordinate geometry to one Ta(1), one Tl(1), and two equivalent Tl(3) atoms. In the third Se site, Se(2) is bonded in a distorted single-bond geometry to one Ta(1), one Tl(3), and one Se(3) atom. In the fourth Se site, Se(3) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(2), and one Se(2) atom. In the fifth Se site, Se(4) is bonded in a distorted see-saw-like geometry to one Ta(1), one Ta(2), one Tl(1), and one Tl(2) atom. In the sixth Se site, Se(5) is bonded in a 4-coordinate geometry to one Ta(1), one Tl(2), one Tl(3), and one Se(6) atom. In the seventh Se site, Se(6) is bonded in a distorted single-bond geometry to one Ta(1) and one Se(5) atom. In the eighth Se site, Se(7) is bonded in a distorted single-bond geometry to one Ta(2), one Tl(4), and one Se(10) atom. In the ninth Se site, Se(8) is bonded in a distorted single-bond geometry to one Ta(2) and one Se(9) atom. In the tenth Se site, Se(9) is bonded in a distorted single-bond geometry to one Ta(2), one Tl(4), and one Se(8) atom. In the eleventh Se site, Se(10) is bonded in a 4-coordinate geometry to one Ta(1), one Ta(2), one Tl(2), and one Se(7) atom. is represented by the CIF file [CIF]
data_Ta2Tl4Se11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.152
_cell_length_b   9.296
_cell_length_c   13.971
_cell_angle_alpha   107.415
_cell_angle_beta   89.331
_cell_angle_gamma   94.230
_symmetry_Int_Tables_number   1
_cell_volume   1007.343
_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
  Ta  Ta0  1  0.663  0.109  0.811  1.0
  Ta  Ta1  1  0.337  0.891  0.189  1.0
  Ta  Ta2  1  0.876  0.367  0.697  1.0
  Ta  Ta3  1  0.124  0.633  0.303  1.0
  Tl  Tl4  1  0.947  0.761  0.018  1.0
  Tl  Tl5  1  0.053  0.239  0.982  1.0
  Tl  Tl6  1  0.788  0.976  0.425  1.0
  Tl  Tl7  1  0.212  0.024  0.575  1.0
  Tl  Tl8  1  0.495  0.275  0.110  1.0
  Tl  Tl9  1  0.505  0.725  0.890  1.0
  Tl  Tl10  1  0.763  0.414  0.418  1.0
  Tl  Tl11  1  0.237  0.586  0.582  1.0
  Se  Se12  1  0.730  0.039  0.959  1.0
  Se  Se13  1  0.270  0.961  0.041  1.0
  Se  Se14  1  0.543  0.690  0.119  1.0
  Se  Se15  1  0.457  0.310  0.881  1.0
  Se  Se16  1  0.737  0.403  0.889  1.0
  Se  Se17  1  0.263  0.597  0.111  1.0
  Se  Se18  1  0.968  0.133  0.750  1.0
  Se  Se19  1  0.032  0.867  0.250  1.0
  Se  Se20  1  0.598  0.076  0.247  1.0
  Se  Se21  1  0.402  0.924  0.753  1.0
  Se  Se22  1  0.651  0.858  0.667  1.0
  Se  Se23  1  0.349  0.142  0.333  1.0
  Se  Se24  1  0.601  0.442  0.648  1.0
  Se  Se25  1  0.399  0.558  0.352  1.0
  Se  Se26  1  0.884  0.492  0.185  1.0
  Se  Se27  1  0.116  0.508  0.815  1.0
  Se  Se28  1  0.946  0.656  0.751  1.0
  Se  Se29  1  0.054  0.344  0.249  1.0
  Se  Se30  1  0.611  0.180  0.628  1.0
  Se  Se31  1  0.389  0.820  0.372  1.0
  Se  Se32  1  0.983  0.710  0.465  1.0
  Se  Se33  1  0.017  0.290  0.535  1.0
[/CIF]
.