data_MgSi2Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.02
_cell_length_b   5.02
_cell_length_c   5.02
_cell_angle_alpha   135.59
_cell_angle_beta   128.55
_cell_angle_gamma   70.27
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSi2Au
_chemical_formula_sum   'Mg1 Si2 Au1'
_cell_volume   68.02
_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
  Mg  Mg1  1  0.0  0.0  0.27  1.0
  Si  Si2  1  0.9  0.0  0.13  1.0
  Si  Si3  1  0.0  0.0  0.84  1.0
  Au  Au0  1  0.9  0.0  0.08  1.0

data_MgSi2Au
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.8
_cell_length_b   4.36
_cell_length_c   5.02
_cell_angle_alpha   115.73
_cell_angle_beta   112.21
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSi2Au
_chemical_formula_sum   'Mg1 Si2 Au1'
_cell_volume   68.02
_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
  Mg  Mg0  1  0.73  0.73  0.73  1.0
  Si  Si1  1  0.16  0.16  0.16  1.0
  Si  Si2  1  0.77  0.87  0.77  1.0
  Au  Au3  1  0.82  0.92  0.82  1.0

Mg Si Si Au
Mg Si Si Au 0 1 - o o 1 3 o o o 1 2 + o - 2 3 - o + 
MgAuSi2 is Indium-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one MgAuSi2 cluster. Mg(1) is bonded in a single-bond geometry to one Si(1) atom. The Mg(1)-Si(1) bond length is 0.55 Å. Au(1) is bonded in a distorted single-bond geometry to one Si(1) and one Si(2) atom. The Au(1)-Si(1) bond length is 0.25 Å. The Au(1)-Si(2) bond length is 1.57 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one Au(1) atom. In the second Si site, Si(2) is bonded in a distorted single-bond geometry to one Au(1) atom.