data_WSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.33
_cell_length_b   3.33
_cell_length_c   14.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   WSe2
_chemical_formula_sum   'W2 Se4'
_cell_volume   137.91
_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
  W  W0  1  0.66  0.96  0.78  1.0
  W  W1  1  0.0  0.92  0.59  1.0
  Se  Se2  1  0.0  0.92  0.45  1.0
  Se  Se3  1  0.66  0.96  0.92  1.0
  Se  Se4  1  0.66  0.96  0.27  1.0
  Se  Se5  1  0.0  0.92  0.1  1.0

data_WSe2
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.33
_cell_length_b   3.33
_cell_length_c   14.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   WSe2
_chemical_formula_sum   'W2 Se4'
_cell_volume   137.91
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
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
  W  W0  2  0.33  0.52  0.59  1.0
  Se  Se1  2  0.33  0.52  0.08  1.0
  Se  Se2  2  0.33  0.52  0.73  1.0

W W Se Se Se Se
W W Se Se Se Se 0 3 o o o 1 2 o o o 2 4 o o o 2 4 - o o 3 5 + o + 3 5 o o + 4 5 o o o 4 5 + o o 4 4 + + o 4 4 o + o 4 4 + o o 5 5 + + o 5 5 o + o 5 5 + o o 
WSe2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one WSe2 cluster. W(1) is bonded in a single-bond geometry to one Se(1) atom. The W(1)-Se(1) bond length is 1.99 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one W(1) and one Se(2) atom. The Se(1)-Se(2) bond length is 2.91 Å. In the second Se site, Se(2) is bonded in a distorted bent 120 degrees geometry to one Se(1) and one Se(2) atom. The Se(2)-Se(2) bond length is 2.70 Å.