data_CaTlSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.23
_cell_length_b   4.23
_cell_length_c   6.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaTlSe2
_chemical_formula_sum   'Ca1 Tl1 Se2'
_cell_volume   109.96
_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
  Ca  Ca0  1  0.0  0.0  0.0  1.0
  Tl  Tl3  1  0.12  0.12  0.07  1.0
  Se  Se1  1  0.12  0.12  0.0  1.0
  Se  Se2  1  0.0  0.0  0.07  1.0

data_CaTlSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.99
_cell_length_b   5.99
_cell_length_c   6.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CaTlSe2
_chemical_formula_sum   'Ca2 Tl2 Se4'
_cell_volume   219.91
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Ca  Ca0  2  0.0  0.0  0.0  1.0
  Tl  Tl1  2  0.12  0.0  0.07  1.0
  Se  Se2  2  0.0  0.0  0.07  1.0
  Se  Se3  2  0.12  0.0  0.0  1.0

Ca Tl Se Se
Ca Tl Se Se 0 3 o o o 1 2 o o o 
CaSeTlSe crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two calcium selenide molecules and two thallium selenide (tlse) molecules.