data_Ac3Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.48
_cell_length_b   6.48
_cell_length_c   6.48
_cell_angle_alpha   134.57
_cell_angle_beta   134.57
_cell_angle_gamma   66.2
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ac3Au
_chemical_formula_sum   'Ac3 Au1'
_cell_volume   135.86
_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
  Ac  Ac0  1  0.0  0.5  0.71  1.0
  Ac  Ac1  1  0.5  0.0  0.71  1.0
  Ac  Ac2  1  0.0  0.0  0.43  1.0
  Au  Au3  1  0.0  0.0  0.0  1.0

data_Ac3Au
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.08
_cell_length_b   7.08
_cell_length_c   6.48
_cell_angle_alpha   90.0
_cell_angle_beta   123.1
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ac3Au
_chemical_formula_sum   'Ac6 Au2'
_cell_volume   271.72
_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
  Ac  Ac0  4  0.04  0.25  0.79  1.0
  Ac  Ac1  2  0.07  0.5  0.57  1.0
  Au  Au2  2  0.0  0.0  0.0  1.0

Ac Ac Ac Au
Ac3Au crystallizes in the monoclinic Cm space group. There are two inequivalent Ac sites. In the first Ac site, Ac(1) is bonded in a distorted single-bond geometry to one Ac(2) and two equivalent Au(1) atoms. The Ac(1)-Ac(2) bond length is 2.35 Å. There is one shorter (2.34 Å) and one longer (3.29 Å) Ac(1)-Au(1) bond length. In the second Ac site, Ac(2) is bonded in a 4-coordinate geometry to two equivalent Ac(1) and two equivalent Au(1) atoms. There is one shorter (2.77 Å) and one longer (3.71 Å) Ac(2)-Au(1) bond length. Au(1) is bonded in a 6-coordinate geometry to two equivalent Ac(2) and four equivalent Ac(1) atoms.