data_HfTlSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.56
_cell_length_b   9.56
_cell_length_c   9.56
_cell_angle_alpha   22.39
_cell_angle_beta   22.39
_cell_angle_gamma   22.39
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfTlSe2
_chemical_formula_sum   'Hf1 Tl1 Se2'
_cell_volume   111.25
_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
  Hf  Hf0  1  0.0  0.0  0.0  1.0
  Tl  Tl3  1  0.0  0.0  0.98  1.0
  Se  Se1  1  0.0  0.0  0.25  1.0
  Se  Se2  1  0.0  0.0  0.7  1.0

data_HfTlSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.43
_cell_length_b   3.71
_cell_length_c   9.56
_cell_angle_alpha   90.0
_cell_angle_beta   102.96
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   HfTlSe2
_chemical_formula_sum   'Hf2 Tl2 Se4'
_cell_volume   222.49
_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
  Hf  Hf0  2  0.0  0.0  0.0  1.0
  Tl  Tl1  2  0.0  0.0  0.02  1.0
  Se  Se2  2  0.0  0.0  0.3  1.0
  Se  Se3  2  0.0  0.0  0.75  1.0

Hf Tl Se Se
Hf Tl Se Se 0 1 o o - 0 2 o o o 0 3 o o - 1 2 o o + 1 3 o o o 
HfTlSe2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two HfTlSe2 clusters. Hf(1) is bonded in a distorted single-bond geometry to one Tl(1) and one Se(1) atom. The Hf(1)-Tl(1) bond length is 0.21 Å. The Hf(1)-Se(1) bond length is 2.43 Å. Tl(1) is bonded in a single-bond geometry to one Hf(1) and one Se(2) atom. The Tl(1)-Se(2) bond length is 2.64 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one Hf(1) atom. In the second Se site, Se(2) is bonded in a single-bond geometry to one Tl(1) atom.