data_SiAs2W
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.01
_cell_length_b   5.01
_cell_length_c   5.01
_cell_angle_alpha   140.63
_cell_angle_beta   125.87
_cell_angle_gamma   68.96
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiAs2W
_chemical_formula_sum   'Si1 As2 W1'
_cell_volume   63.68
_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
  Si  Si2  1  0.0  0.0  0.27  1.0
  As  As0  1  0.0  0.0  0.18  1.0
  As  As1  1  0.0  0.28  0.99  1.0
  W  W3  1  0.69  0.0  0.09  1.0

data_SiAs2W
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.38
_cell_length_b   4.56
_cell_length_c   5.01
_cell_angle_alpha   117.07
_cell_angle_beta   109.68
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiAs2W
_chemical_formula_sum   'Si1 As2 W1'
_cell_volume   63.68
_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
  Si  Si0  1  0.73  0.73  0.73  1.0
  As  As1  1  0.01  0.29  0.29  1.0
  As  As2  1  0.82  0.82  0.82  1.0
  W  W3  1  0.6  0.91  0.6  1.0

Si As As W
Si As As W 0 1 o o o 0 2 o - - 0 2 o o o 0 2 o o - 0 3 - o o 1 2 o - - 1 2 o o - 1 3 - o o 2 3 - o o 2 3 - o + 
WSiAs2 crystallizes in the triclinic P1 space group. W(1) is bonded in a distorted single-bond geometry to one Si(1) and five equivalent As(2) atoms. The W(1)-Si(1) bond length is 1.27 Å. There are a spread of W(1)-As(2) bond distances ranging from 2.86-3.35 Å. Si(1) is bonded in a distorted L-shaped geometry to one W(1), one As(1), and two equivalent As(2) atoms. The Si(1)-As(1) bond length is 0.43 Å. There is one shorter (2.68 Å) and one longer (2.70 Å) Si(1)-As(2) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Si(1) and one As(2) atom. The As(1)-As(2) bond length is 2.23 Å. In the second As site, As(2) is bonded in a 8-coordinate geometry to five equivalent W(1), two equivalent Si(1), and one As(1) atom.