data_Si3Te
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.37
_cell_length_b   5.37
_cell_length_c   5.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Te
_chemical_formula_sum   'Si6 Te2'
_cell_volume   155.05
_cell_formula_units_Z   2
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
  Si  Si0  1  0.34  0.0  0.69  1.0
  Si  Si1  1  0.03  0.0  0.69  1.0
  Si  Si2  1  0.69  0.34  0.0  1.0
  Si  Si3  1  0.69  0.03  0.0  1.0
  Si  Si4  1  0.0  0.69  0.03  1.0
  Si  Si5  1  0.0  0.69  0.34  1.0
  Te  Te6  1  0.69  0.69  0.69  1.0
  Te  Te7  1  0.0  0.0  0.0  1.0

data_Si3Te
_symmetry_space_group_name_H-M   R3
_cell_length_a   7.6
_cell_length_b   7.6
_cell_length_c   9.31
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Si3Te
_chemical_formula_sum   'Si18 Te6'
_cell_volume   465.15
_cell_formula_units_Z   6
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  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+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
  Si  Si0  9  0.0  0.66  0.34  1.0
  Si  Si1  9  0.09  0.88  0.91  1.0
  Te  Te2  3  0.0  0.0  0.0  1.0
  Te  Te3  3  0.0  0.0  0.69  1.0

Si Si Si Si Si Si Te Te
Si3Te crystallizes in the trigonal R3 space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to two equivalent Si(2), one Te(1), and one Te(2) atom. There is one shorter (1.69 Å) and one longer (2.50 Å) Si(1)-Si(2) bond length. The Si(1)-Te(1) bond length is 2.50 Å. The Si(1)-Te(2) bond length is 2.50 Å. In the second Si site, Si(2) is bonded in a 1-coordinate geometry to two equivalent Si(1), one Te(1), and one Te(2) atom. The Si(2)-Te(1) bond length is 2.50 Å. The Si(2)-Te(2) bond length is 1.69 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a distorted hexagonal planar geometry to three equivalent Si(1) and three equivalent Si(2) atoms. In the second Te site, Te(2) is bonded in a 3-coordinate geometry to three equivalent Si(1) and three equivalent Si(2) atoms.