The material structure described by Mo9Tl2Se11 crystallizes in the trigonal R-3 space group. There are three inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one Se(2), one Se(4), and three equivalent Se(1) atoms to form distorted MoSe5 square pyramids that share corners with three equivalent Mo(2)Se5 square pyramids,  a cornercorner with one Tl(2)Se4 trigonal pyramid,  an edgeedge with one Mo(2)Se5 square pyramid, and edges with four equivalent Mo(1)Se5 square pyramids. In the second Mo site, Mo(2) is bonded to one Se(1), one Se(3), one Se(5), and two equivalent Se(2) atoms to form distorted MoSe5 square pyramids that share corners with three equivalent Mo(1)Se5 square pyramids, corners with three equivalent Tl(2)Se4 trigonal pyramids,  an edgeedge with one Mo(1)Se5 square pyramid, and edges with two equivalent Mo(2)Se5 square pyramids. In the third Mo site, Mo(3) is bonded in a distorted see-saw-like geometry to one Se(2) and three equivalent Se(3) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a single-bond geometry to one Se(4) atom. In the second Tl site, Tl(2) is bonded to one Se(5) and three equivalent Se(2) atoms to form distorted TlSe4 trigonal pyramids that share corners with three equivalent Mo(1)Se5 square pyramids and corners with nine equivalent Mo(2)Se5 square pyramids. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to one Mo(2) and three equivalent Mo(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), and one Tl(2) atom. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one Mo(2) and three equivalent Mo(3) atoms. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to three equivalent Mo(1) and one Tl(1) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to three equivalent Mo(2) and one Tl(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tl2Mo9Se11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.519
_cell_length_b   13.519
_cell_length_c   13.519
_cell_angle_alpha   42.576
_cell_angle_beta   42.576
_cell_angle_gamma   42.576
_symmetry_Int_Tables_number   1
_cell_volume   1024.249
_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
  Tl  Tl0  1  0.830  0.830  0.830  1.0
  Tl  Tl1  1  0.170  0.170  0.170  1.0
  Tl  Tl2  1  0.268  0.268  0.268  1.0
  Tl  Tl3  1  0.732  0.732  0.732  1.0
  Mo  Mo4  1  0.865  0.046  0.182  1.0
  Mo  Mo5  1  0.046  0.182  0.865  1.0
  Mo  Mo6  1  0.182  0.865  0.046  1.0
  Mo  Mo7  1  0.135  0.954  0.818  1.0
  Mo  Mo8  1  0.954  0.818  0.135  1.0
  Mo  Mo9  1  0.818  0.135  0.954  1.0
  Mo  Mo10  1  0.392  0.260  0.570  1.0
  Mo  Mo11  1  0.260  0.570  0.392  1.0
  Mo  Mo12  1  0.570  0.392  0.260  1.0
  Mo  Mo13  1  0.608  0.740  0.430  1.0
  Mo  Mo14  1  0.740  0.430  0.608  1.0
  Mo  Mo15  1  0.430  0.608  0.740  1.0
  Mo  Mo16  1  0.307  0.479  0.624  1.0
  Mo  Mo17  1  0.479  0.624  0.307  1.0
  Mo  Mo18  1  0.624  0.307  0.479  1.0
  Mo  Mo19  1  0.693  0.521  0.376  1.0
  Mo  Mo20  1  0.521  0.376  0.693  1.0
  Mo  Mo21  1  0.376  0.693  0.521  1.0
  Se  Se22  1  0.651  0.005  0.264  1.0
  Se  Se23  1  0.005  0.264  0.651  1.0
  Se  Se24  1  0.264  0.651  0.005  1.0
  Se  Se25  1  0.349  0.995  0.736  1.0
  Se  Se26  1  0.995  0.736  0.349  1.0
  Se  Se27  1  0.736  0.349  0.995  1.0
  Se  Se28  1  0.706  0.089  0.441  1.0
  Se  Se29  1  0.089  0.441  0.706  1.0
  Se  Se30  1  0.441  0.706  0.089  1.0
  Se  Se31  1  0.294  0.911  0.559  1.0
  Se  Se32  1  0.911  0.559  0.294  1.0
  Se  Se33  1  0.559  0.294  0.911  1.0
  Se  Se34  1  0.450  0.168  0.785  1.0
  Se  Se35  1  0.168  0.785  0.450  1.0
  Se  Se36  1  0.785  0.450  0.168  1.0
  Se  Se37  1  0.550  0.832  0.215  1.0
  Se  Se38  1  0.832  0.215  0.550  1.0
  Se  Se39  1  0.215  0.550  0.832  1.0
  Se  Se40  1  0.086  0.086  0.086  1.0
  Se  Se41  1  0.914  0.914  0.914  1.0
  Se  Se42  1  0.352  0.352  0.352  1.0
  Se  Se43  1  0.648  0.648  0.648  1.0
[/CIF]
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The material structure described by Mo9Tl2Se11 crystallizes in the trigonal R-3 space group. There are three inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one Se(2), one Se(4), and three equivalent Se(1) atoms to form distorted MoSe5 square pyramids that share corners with three equivalent Mo(2)Se5 square pyramids,  a cornercorner with one Tl(2)Se4 trigonal pyramid,  an edgeedge with one Mo(2)Se5 square pyramid, and edges with four equivalent Mo(1)Se5 square pyramids. In the second Mo site, Mo(2) is bonded to one Se(1), one Se(3), one Se(5), and two equivalent Se(2) atoms to form distorted MoSe5 square pyramids that share corners with three equivalent Mo(1)Se5 square pyramids, corners with three equivalent Tl(2)Se4 trigonal pyramids,  an edgeedge with one Mo(1)Se5 square pyramid, and edges with two equivalent Mo(2)Se5 square pyramids. In the third Mo site, Mo(3) is bonded in a distorted see-saw-like geometry to one Se(2) and three equivalent Se(3) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a single-bond geometry to one Se(4) atom. In the second Tl site, Tl(2) is bonded to one Se(5) and three equivalent Se(2) atoms to form distorted TlSe4 trigonal pyramids that share corners with three equivalent Mo(1)Se5 square pyramids and corners with nine equivalent Mo(2)Se5 square pyramids. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to one Mo(2) and three equivalent Mo(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one Mo(1), one Mo(3), two equivalent Mo(2), and one Tl(2) atom. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one Mo(2) and three equivalent Mo(3) atoms. In the fourth Se site, Se(4) is bonded in a 4-coordinate geometry to three equivalent Mo(1) and one Tl(1) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to three equivalent Mo(2) and one Tl(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tl2Mo9Se11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.519
_cell_length_b   13.519
_cell_length_c   13.519
_cell_angle_alpha   42.576
_cell_angle_beta   42.576
_cell_angle_gamma   42.576
_symmetry_Int_Tables_number   1
_cell_volume   1024.249
_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
  Tl  Tl0  1  0.830  0.830  0.830  1.0
  Tl  Tl1  1  0.170  0.170  0.170  1.0
  Tl  Tl2  1  0.268  0.268  0.268  1.0
  Tl  Tl3  1  0.732  0.732  0.732  1.0
  Mo  Mo4  1  0.865  0.046  0.182  1.0
  Mo  Mo5  1  0.046  0.182  0.865  1.0
  Mo  Mo6  1  0.182  0.865  0.046  1.0
  Mo  Mo7  1  0.135  0.954  0.818  1.0
  Mo  Mo8  1  0.954  0.818  0.135  1.0
  Mo  Mo9  1  0.818  0.135  0.954  1.0
  Mo  Mo10  1  0.392  0.260  0.570  1.0
  Mo  Mo11  1  0.260  0.570  0.392  1.0
  Mo  Mo12  1  0.570  0.392  0.260  1.0
  Mo  Mo13  1  0.608  0.740  0.430  1.0
  Mo  Mo14  1  0.740  0.430  0.608  1.0
  Mo  Mo15  1  0.430  0.608  0.740  1.0
  Mo  Mo16  1  0.307  0.479  0.624  1.0
  Mo  Mo17  1  0.479  0.624  0.307  1.0
  Mo  Mo18  1  0.624  0.307  0.479  1.0
  Mo  Mo19  1  0.693  0.521  0.376  1.0
  Mo  Mo20  1  0.521  0.376  0.693  1.0
  Mo  Mo21  1  0.376  0.693  0.521  1.0
  Se  Se22  1  0.651  0.005  0.264  1.0
  Se  Se23  1  0.005  0.264  0.651  1.0
  Se  Se24  1  0.264  0.651  0.005  1.0
  Se  Se25  1  0.349  0.995  0.736  1.0
  Se  Se26  1  0.995  0.736  0.349  1.0
  Se  Se27  1  0.736  0.349  0.995  1.0
  Se  Se28  1  0.706  0.089  0.441  1.0
  Se  Se29  1  0.089  0.441  0.706  1.0
  Se  Se30  1  0.441  0.706  0.089  1.0
  Se  Se31  1  0.294  0.911  0.559  1.0
  Se  Se32  1  0.911  0.559  0.294  1.0
  Se  Se33  1  0.559  0.294  0.911  1.0
  Se  Se34  1  0.450  0.168  0.785  1.0
  Se  Se35  1  0.168  0.785  0.450  1.0
  Se  Se36  1  0.785  0.450  0.168  1.0
  Se  Se37  1  0.550  0.832  0.215  1.0
  Se  Se38  1  0.832  0.215  0.550  1.0
  Se  Se39  1  0.215  0.550  0.832  1.0
  Se  Se40  1  0.086  0.086  0.086  1.0
  Se  Se41  1  0.914  0.914  0.914  1.0
  Se  Se42  1  0.352  0.352  0.352  1.0
  Se  Se43  1  0.648  0.648  0.648  1.0
[/CIF]
.