data_NaTeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.13
_cell_length_b   5.13
_cell_length_c   5.13
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaTeSe2
_chemical_formula_sum   'Na1 Te1 Se2'
_cell_volume   95.47
_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
  Te  Te3  1  0.63  0.63  0.63  1.0
  Se  Se1  1  0.44  0.44  0.44  1.0
  Se  Se2  1  0.81  0.81  0.81  1.0

data_NaTeSe2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.13
_cell_length_b   5.13
_cell_length_c   12.57
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NaTeSe2
_chemical_formula_sum   'Na3 Te3 Se6'
_cell_volume   286.42
_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
  Na  Na0  3  0.0  0.0  0.0  1.0
  Te  Te1  3  0.0  0.0  0.37  1.0
  Se  Se2  3  0.0  0.0  0.19  1.0
  Se  Se3  3  0.0  0.0  0.56  1.0

Na Te Se Se
Na Te Se Se 0 3 - - - 0 1 - - o 0 1 - o - 0 1 o - - 1 2 o o o 1 3 o o o 2 3 - o o 2 3 o - o 2 3 o o - 
NaTeSe2 crystallizes in the trigonal R3m space group. Na(1) is bonded in a distorted single-bond geometry to three equivalent Te(1), one Se(2), and three equivalent Se(1) atoms. All Na(1)-Te(1) bond lengths are 3.00 Å. The Na(1)-Se(2) bond length is 2.34 Å. All Na(1)-Se(1) bond lengths are 3.26 Å. Te(1) is bonded to three equivalent Na(1), one Se(1), and one Se(2) atom to form distorted corner-sharing TeNa3Se2 trigonal bipyramids. The Te(1)-Se(1) bond length is 2.34 Å. The Te(1)-Se(2) bond length is 2.34 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to three equivalent Na(1) and one Te(1) atom. In the second Se site, Se(2) is bonded in a linear geometry to one Na(1) and one Te(1) atom.