data_Si2Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.01
_cell_length_b   6.01
_cell_length_c   7.66
_cell_angle_alpha   124.57
_cell_angle_beta   124.57
_cell_angle_gamma   26.54
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2Au
_chemical_formula_sum   'Si4 Au2'
_cell_volume   100.56
_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
  Si  Si2  1  0.82  0.0  0.01  1.0
  Si  Si3  1  0.9  0.0  0.5  1.0
  Si  Si4  1  0.42  0.0  0.21  1.0
  Si  Si5  1  0.34  0.0  0.72  1.0
  Au  Au0  1  0.03  0.0  0.77  1.0
  Au  Au1  1  0.22  0.0  0.45  1.0

data_Si2Au
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.76
_cell_length_b   6.01
_cell_length_c   6.52
_cell_angle_alpha   75.16
_cell_angle_beta   77.78
_cell_angle_gamma   76.73
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Si2Au
_chemical_formula_sum   'Si4 Au2'
_cell_volume   100.56
_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
  Si  Si0  2  0.0  0.2  0.1  1.0
  Si  Si1  2  0.0  0.39  0.39  1.0
  Au  Au2  2  0.0  0.25  0.66  1.0

Si Si Si Si Au Au
Si Si Si Si Au Au 0 3 + - - 0 3 o o - 0 0 + - o 0 2 + o o 0 4 + o - 0 5 + o o 1 5 + o o 1 4 + o o 1 3 + o o 1 2 o o o 1 2 + - o 2 4 o o - 2 5 o o o 2 2 + - o 3 5 o o o 3 4 o o o 
AuSi2 crystallizes in the triclinic P-1 space group. Au(1) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. There is one shorter (2.74 Å) and one longer (2.81 Å) Au(1)-Si(1) bond length. There is one shorter (1.74 Å) and one longer (2.12 Å) Au(1)-Si(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to two equivalent Au(1), one Si(2), and two equivalent Si(1) atoms. The Si(1)-Si(2) bond length is 2.46 Å. Both Si(1)-Si(1) bond lengths are 2.76 Å. In the second Si site, Si(2) is bonded in a 2-coordinate geometry to two equivalent Au(1) and one Si(1) atom.