data_Bi2AsW2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.66
_cell_length_b   6.66
_cell_length_c   6.66
_cell_angle_alpha   138.97
_cell_angle_beta   138.97
_cell_angle_gamma   59.43
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Bi2AsW2
_chemical_formula_sum   'Bi2 As1 W2'
_cell_volume   126.23
_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
  Bi  Bi1  1  0.0  0.0  0.22  1.0
  Bi  Bi2  1  0.0  0.0  0.35  1.0
  As  As0  1  0.0  0.0  0.0  1.0
  W  W3  1  0.0  0.34  0.89  1.0
  W  W4  1  0.34  0.0  0.89  1.0

data_Bi2AsW2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.61
_cell_length_b   6.61
_cell_length_c   6.66
_cell_angle_alpha   90.0
_cell_angle_beta   119.71
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Bi2AsW2
_chemical_formula_sum   'Bi4 As2 W4'
_cell_volume   252.46
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Bi  Bi0  2  0.22  0.0  0.22  1.0
  Bi  Bi1  2  0.35  0.0  0.35  1.0
  As  As2  2  0.0  0.0  0.0  1.0
  W  W3  4  0.23  0.33  0.56  1.0

Bi Bi As W W
Bi Bi As W W 0 1 o o o 0 2 o o o 1 3 o o o 1 4 o o o 3 4 o o o 
W2Bi2As crystallizes in the monoclinic Cm space group. W(1) is bonded in a 4-coordinate geometry to one W(1), two equivalent Bi(2), and one As(1) atom. The W(1)-W(1) bond length is 2.21 Å. There is one shorter (2.42 Å) and one longer (2.92 Å) W(1)-Bi(2) bond length. The W(1)-As(1) bond length is 2.81 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a linear geometry to one Bi(2) and one As(1) atom. The Bi(1)-Bi(2) bond length is 0.86 Å. The Bi(1)-As(1) bond length is 1.48 Å. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to four equivalent W(1) and one Bi(1) atom. As(1) is bonded in a distorted single-bond geometry to two equivalent W(1) and one Bi(1) atom.