data_Si3Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.49
_cell_length_b   4.49
_cell_length_c   3.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   104.83
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Au
_chemical_formula_sum   'Si3 Au1'
_cell_volume   65.16
_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  Si1  1  0.37  0.22  0.67  1.0
  Si  Si2  1  0.37  0.78  0.67  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Au  Au0  1  0.74  0.0  0.0  1.0

data_Si3Au
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.34
_cell_length_b   4.49
_cell_length_c   4.49
_cell_angle_alpha   104.83
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Au
_chemical_formula_sum   'Si3 Au1'
_cell_volume   65.16
_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  0.0  0.0  0.0  1.0
  Si  Si1  1  0.67  0.37  0.22  1.0
  Si  Si2  1  0.67  0.37  0.78  1.0
  Au  Au3  1  0.0  0.74  0.0  1.0

Si Si Si Au
Si Si Si Au 0 2 o o + 0 3 o o + 0 1 o - o 1 2 o + + 1 3 o + + 2 3 - o o 
AuSi3 crystallizes in the triclinic P1 space group. Au(1) is bonded in a 2-coordinate geometry to one Si(2), one Si(3), and two equivalent Si(1) atoms. The Au(1)-Si(2) bond length is 2.02 Å. The Au(1)-Si(3) bond length is 1.17 Å. There is one shorter (2.40 Å) and one longer (3.10 Å) Au(1)-Si(1) bond length. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to two equivalent Au(1), two equivalent Si(2), and two equivalent Si(3) atoms. There is one shorter (1.99 Å) and one longer (2.50 Å) Si(1)-Si(2) bond length. There is one shorter (2.02 Å) and one longer (2.82 Å) Si(1)-Si(3) bond length. In the second Si site, Si(2) is bonded in a distorted single-bond geometry to one Au(1) and two equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a single-bond geometry to one Au(1) and two equivalent Si(1) atoms.