The structure described by TlCu7Se4 crystallizes in the triclinic P1 space group. There are seven inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to two equivalent Cu(5), one Se(1), and two equivalent Se(2) atoms. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to two equivalent Cu(5), one Se(1), one Se(3), and two equivalent Se(4) atoms. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(4) atoms. In the fourth Cu site, Cu(4) is bonded in a 3-coordinate geometry to one Cu(5), one Se(3), and two equivalent Se(1) atoms. In the fifth Cu site, Cu(5) is bonded in a 9-coordinate geometry to one Cu(4), two equivalent Cu(1), two equivalent Cu(2), one Se(2), one Se(4), and two equivalent Se(1) atoms. In the sixth Cu site, Cu(6) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(2) atoms. In the seventh Cu site, Cu(7) is bonded in a distorted trigonal non-coplanar geometry to one Se(4) and two equivalent Se(3) atoms. Tl(1) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(1) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 8-coordinate geometry to one Cu(1), one Cu(2), two equivalent Cu(4), two equivalent Cu(5), and two equivalent Tl(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to one Cu(3), one Cu(5), two equivalent Cu(1), and two equivalent Cu(6) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one Cu(2), one Cu(4), one Cu(6), two equivalent Cu(7), and one Tl(1) atom. In the fourth Se site, Se(4) is bonded in a 8-coordinate geometry to one Cu(5), one Cu(6), one Cu(7), two equivalent Cu(2), two equivalent Cu(3), and one Tl(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_TlCu7Se4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.008
_cell_length_b   7.681
_cell_length_c   7.591
_cell_angle_alpha   87.205
_cell_angle_beta   74.622
_cell_angle_gamma   75.523
_symmetry_Int_Tables_number   1
_cell_volume   218.171
_cell_formula_units_Z   1
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  0.997  0.990  0.009  1.0
  Cu  Cu1  1  0.030  0.351  0.600  1.0
  Cu  Cu2  1  0.324  0.898  0.455  1.0
  Cu  Cu3  1  0.347  0.600  0.648  1.0
  Cu  Cu4  1  0.641  0.393  0.356  1.0
  Cu  Cu5  1  0.667  0.125  0.558  1.0
  Cu  Cu6  1  0.752  0.547  0.882  1.0
  Cu  Cu7  1  0.029  0.644  0.383  1.0
  Se  Se8  1  0.252  0.185  0.311  1.0
  Se  Se9  1  0.418  0.329  0.831  1.0
  Se  Se10  1  0.610  0.665  0.188  1.0
  Se  Se11  1  0.713  0.818  0.674  1.0
[/CIF]
.
The structure described by TlCu7Se4 crystallizes in the triclinic P1 space group. There are seven inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to two equivalent Cu(5), one Se(1), and two equivalent Se(2) atoms. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to two equivalent Cu(5), one Se(1), one Se(3), and two equivalent Se(4) atoms. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(4) atoms. In the fourth Cu site, Cu(4) is bonded in a 3-coordinate geometry to one Cu(5), one Se(3), and two equivalent Se(1) atoms. In the fifth Cu site, Cu(5) is bonded in a 9-coordinate geometry to one Cu(4), two equivalent Cu(1), two equivalent Cu(2), one Se(2), one Se(4), and two equivalent Se(1) atoms. In the sixth Cu site, Cu(6) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(2) atoms. In the seventh Cu site, Cu(7) is bonded in a distorted trigonal non-coplanar geometry to one Se(4) and two equivalent Se(3) atoms. Tl(1) is bonded in a 4-coordinate geometry to one Se(3), one Se(4), and two equivalent Se(1) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 8-coordinate geometry to one Cu(1), one Cu(2), two equivalent Cu(4), two equivalent Cu(5), and two equivalent Tl(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to one Cu(3), one Cu(5), two equivalent Cu(1), and two equivalent Cu(6) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one Cu(2), one Cu(4), one Cu(6), two equivalent Cu(7), and one Tl(1) atom. In the fourth Se site, Se(4) is bonded in a 8-coordinate geometry to one Cu(5), one Cu(6), one Cu(7), two equivalent Cu(2), two equivalent Cu(3), and one Tl(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_TlCu7Se4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.008
_cell_length_b   7.681
_cell_length_c   7.591
_cell_angle_alpha   87.205
_cell_angle_beta   74.622
_cell_angle_gamma   75.523
_symmetry_Int_Tables_number   1
_cell_volume   218.171
_cell_formula_units_Z   1
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  0.997  0.990  0.009  1.0
  Cu  Cu1  1  0.030  0.351  0.600  1.0
  Cu  Cu2  1  0.324  0.898  0.455  1.0
  Cu  Cu3  1  0.347  0.600  0.648  1.0
  Cu  Cu4  1  0.641  0.393  0.356  1.0
  Cu  Cu5  1  0.667  0.125  0.558  1.0
  Cu  Cu6  1  0.752  0.547  0.882  1.0
  Cu  Cu7  1  0.029  0.644  0.383  1.0
  Se  Se8  1  0.252  0.185  0.311  1.0
  Se  Se9  1  0.418  0.329  0.831  1.0
  Se  Se10  1  0.610  0.665  0.188  1.0
  Se  Se11  1  0.713  0.818  0.674  1.0
[/CIF]
.