data_NaTlSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.66
_cell_length_b   5.66
_cell_length_c   3.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   108.61
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaTlSe2
_chemical_formula_sum   'Na1 Tl1 Se2'
_cell_volume   100.88
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Tl  Tl3  1  0.3  0.0  0.0  1.0
  Se  Se1  1  0.65  0.3  0.66  1.0
  Se  Se2  1  0.65  0.7  0.66  1.0

data_NaTlSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.32
_cell_length_b   5.66
_cell_length_c   5.66
_cell_angle_alpha   108.61
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaTlSe2
_chemical_formula_sum   'Na1 Tl1 Se2'
_cell_volume   100.88
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Tl  Tl1  1  0.0  0.3  0.0  1.0
  Se  Se2  1  0.66  0.65  0.3  1.0
  Se  Se3  1  0.66  0.65  0.7  1.0

Na Tl Se Se
NaTlSe2 crystallizes in the triclinic P1 space group. Na(1) is bonded in a 2-coordinate geometry to one Tl(1), one Se(1), and two equivalent Se(2) atoms. The Na(1)-Tl(1) bond length is 1.72 Å. The Na(1)-Se(1) bond length is 3.19 Å. There is one shorter (2.43 Å) and one longer (3.07 Å) Na(1)-Se(2) bond length. Tl(1) is bonded in a 2-coordinate geometry to one Na(1), one Se(2), and two equivalent Se(1) atoms. The Tl(1)-Se(2) bond length is 3.19 Å. There is one shorter (2.43 Å) and one longer (3.07 Å) Tl(1)-Se(1) bond length. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Tl(1), and one Se(2) atom. The Se(1)-Se(2) bond length is 2.27 Å. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to two equivalent Na(1), one Tl(1), and one Se(1) atom.