The compound described by AgTlSe2 crystallizes in the hexagonal P6_3/mcm space group. Ag(1) is bonded to one Tl(1) and four equivalent Se(1) atoms to form AgTlSe4 square pyramids that share corners with four equivalent Tl(2)Se6 pentagonal pyramids, corners with six equivalent Ag(1)TlSe4 square pyramids, and edges with two equivalent Tl(2)Se6 pentagonal pyramids. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a trigonal planar geometry to three equivalent Ag(1) atoms. In the second Tl site, Tl(2) is bonded to six equivalent Se(1) atoms to form distorted TlSe6 pentagonal pyramids that share corners with six equivalent Ag(1)TlSe4 square pyramids, edges with three equivalent Ag(1)TlSe4 square pyramids, and faces with two equivalent Tl(2)Se6 pentagonal pyramids. Se(1) is bonded in a 4-coordinate geometry to two equivalent Ag(1) and two equivalent Tl(2) atoms. is represented by the CIF card [CIF]
data_TlAgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.486
_cell_length_b   10.486
_cell_length_c   7.431
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   707.620
_cell_formula_units_Z   6
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  0.000  0.000  0.250  1.0
  Tl  Tl1  1  0.000  0.000  0.750  1.0
  Tl  Tl2  1  0.333  0.667  0.250  1.0
  Tl  Tl3  1  0.333  0.667  0.750  1.0
  Tl  Tl4  1  0.667  0.333  0.750  1.0
  Tl  Tl5  1  0.667  0.333  0.250  1.0
  Ag  Ag6  1  0.291  0.291  0.750  1.0
  Ag  Ag7  1  0.000  0.291  0.250  1.0
  Ag  Ag8  1  0.709  0.709  0.250  1.0
  Ag  Ag9  1  0.000  0.709  0.750  1.0
  Ag  Ag10  1  0.709  0.000  0.750  1.0
  Ag  Ag11  1  0.291  0.000  0.250  1.0
  Se  Se12  1  0.406  0.203  0.500  1.0
  Se  Se13  1  0.797  0.594  0.500  1.0
  Se  Se14  1  0.797  0.203  0.500  1.0
  Se  Se15  1  0.594  0.797  0.500  1.0
  Se  Se16  1  0.203  0.406  0.500  1.0
  Se  Se17  1  0.203  0.797  0.500  1.0
  Se  Se18  1  0.406  0.203  0.000  1.0
  Se  Se19  1  0.797  0.594  0.000  1.0
  Se  Se20  1  0.203  0.797  0.000  1.0
  Se  Se21  1  0.594  0.797  0.000  1.0
  Se  Se22  1  0.203  0.406  0.000  1.0
  Se  Se23  1  0.797  0.203  0.000  1.0
[/CIF]
.
The compound described by AgTlSe2 crystallizes in the hexagonal P6_3/mcm space group. Ag(1) is bonded to one Tl(1) and four equivalent Se(1) atoms to form AgTlSe4 square pyramids that share corners with four equivalent Tl(2)Se6 pentagonal pyramids, corners with six equivalent Ag(1)TlSe4 square pyramids, and edges with two equivalent Tl(2)Se6 pentagonal pyramids. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a trigonal planar geometry to three equivalent Ag(1) atoms. In the second Tl site, Tl(2) is bonded to six equivalent Se(1) atoms to form distorted TlSe6 pentagonal pyramids that share corners with six equivalent Ag(1)TlSe4 square pyramids, edges with three equivalent Ag(1)TlSe4 square pyramids, and faces with two equivalent Tl(2)Se6 pentagonal pyramids. Se(1) is bonded in a 4-coordinate geometry to two equivalent Ag(1) and two equivalent Tl(2) atoms. is represented by the CIF card [CIF]
data_TlAgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.486
_cell_length_b   10.486
_cell_length_c   7.431
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   707.620
_cell_formula_units_Z   6
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  0.000  0.000  0.250  1.0
  Tl  Tl1  1  0.000  0.000  0.750  1.0
  Tl  Tl2  1  0.333  0.667  0.250  1.0
  Tl  Tl3  1  0.333  0.667  0.750  1.0
  Tl  Tl4  1  0.667  0.333  0.750  1.0
  Tl  Tl5  1  0.667  0.333  0.250  1.0
  Ag  Ag6  1  0.291  0.291  0.750  1.0
  Ag  Ag7  1  0.000  0.291  0.250  1.0
  Ag  Ag8  1  0.709  0.709  0.250  1.0
  Ag  Ag9  1  0.000  0.709  0.750  1.0
  Ag  Ag10  1  0.709  0.000  0.750  1.0
  Ag  Ag11  1  0.291  0.000  0.250  1.0
  Se  Se12  1  0.406  0.203  0.500  1.0
  Se  Se13  1  0.797  0.594  0.500  1.0
  Se  Se14  1  0.797  0.203  0.500  1.0
  Se  Se15  1  0.594  0.797  0.500  1.0
  Se  Se16  1  0.203  0.406  0.500  1.0
  Se  Se17  1  0.203  0.797  0.500  1.0
  Se  Se18  1  0.406  0.203  0.000  1.0
  Se  Se19  1  0.797  0.594  0.000  1.0
  Se  Se20  1  0.203  0.797  0.000  1.0
  Se  Se21  1  0.594  0.797  0.000  1.0
  Se  Se22  1  0.203  0.406  0.000  1.0
  Se  Se23  1  0.797  0.203  0.000  1.0
[/CIF]
.