data_PbW2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.67
_cell_length_b   4.67
_cell_length_c   4.67
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PbW2Se
_chemical_formula_sum   'Pb1 W2 Se1'
_cell_volume   71.98
_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
  Pb  Pb0  1  0.3  0.3  0.3  1.0
  W  W2  1  0.95  0.95  0.95  1.0
  W  W3  1  0.65  0.65  0.65  1.0
  Se  Se1  1  0.0  0.0  0.0  1.0

data_PbW2Se
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.67
_cell_length_b   4.67
_cell_length_c   11.44
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   PbW2Se
_chemical_formula_sum   'Pb3 W6 Se3'
_cell_volume   215.94
_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
  Pb  Pb0  3  0.0  0.0  0.7  1.0
  W  W1  3  0.0  0.0  0.05  1.0
  W  W2  3  0.0  0.0  0.35  1.0
  Se  Se3  3  0.0  0.0  0.0  1.0

Pb W W Se
W2PbSe crystallizes in the trigonal R3m space group. There are two inequivalent W sites. In the first W site, W(1) is bonded in a single-bond geometry to four equivalent W(2), three equivalent Pb(1), and one Se(1) atom. There are three shorter (2.72 Å) and one longer (3.45 Å) W(1)-W(2) bond length. All W(1)-Pb(1) bond lengths are 2.70 Å. The W(1)-Se(1) bond length is 0.54 Å. In the second W site, W(2) is bonded in a 10-coordinate geometry to four equivalent W(1), three equivalent Pb(1), and three equivalent Se(1) atoms. All W(2)-Pb(1) bond lengths are 2.70 Å. All W(2)-Se(1) bond lengths are 2.70 Å. Pb(1) is bonded in a 10-coordinate geometry to three equivalent W(1), three equivalent W(2), and four equivalent Se(1) atoms. There are three shorter (2.72 Å) and one longer (3.45 Å) Pb(1)-Se(1) bond length. Se(1) is bonded in a single-bond geometry to one W(1), three equivalent W(2), and four equivalent Pb(1) atoms.