data_CdTeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.11
_cell_length_b   5.11
_cell_length_c   5.11
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CdTeSe2
_chemical_formula_sum   'Cd1 Te1 Se2'
_cell_volume   94.17
_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
  Cd  Cd0  1  0.61  0.61  0.61  1.0
  Te  Te3  1  0.42  0.42  0.42  1.0
  Se  Se1  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.81  0.81  0.81  1.0

data_CdTeSe2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.11
_cell_length_b   5.11
_cell_length_c   12.51
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CdTeSe2
_chemical_formula_sum   'Cd3 Te3 Se6'
_cell_volume   282.5
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Cd  Cd0  3  0.0  0.0  0.39  1.0
  Te  Te1  3  0.0  0.0  0.58  1.0
  Se  Se2  3  0.0  0.0  -0.0  1.0
  Se  Se3  3  0.0  0.0  0.19  1.0

Cd Te Se Se
CdTeSe2 crystallizes in the trigonal R3m space group. Cd(1) is bonded in a 5-coordinate geometry to one Te(1), one Se(2), and three equivalent Se(1) atoms. The Cd(1)-Te(1) bond length is 2.43 Å. The Cd(1)-Se(2) bond length is 2.43 Å. All Cd(1)-Se(1) bond lengths are 3.03 Å. Te(1) is bonded in a 1-coordinate geometry to one Cd(1) and three equivalent Se(1) atoms. All Te(1)-Se(1) bond lengths are 3.13 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Cd(1), three equivalent Te(1), and one Se(2) atom to form distorted edge-sharing SeCd3Te3Se hexagonal pyramids. The Se(1)-Se(2) bond length is 2.43 Å. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to one Cd(1) and one Se(1) atom.