The compound described by Au3Cu is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. Au(1) is bonded to eight equivalent Au(1) and four equivalent Cu(1) atoms to form distorted AuCu4Au8 cuboctahedra that share corners with four equivalent Cu(1)Au12 cuboctahedra, corners with fourteen equivalent Au(1)Cu4Au8 cuboctahedra, edges with six equivalent Cu(1)Au12 cuboctahedra, edges with twelve equivalent Au(1)Cu4Au8 cuboctahedra, faces with four equivalent Cu(1)Au12 cuboctahedra, and faces with sixteen equivalent Au(1)Cu4Au8 cuboctahedra. Cu(1) is bonded to twelve equivalent Au(1) atoms to form CuAu12 cuboctahedra that share corners with six equivalent Cu(1)Au12 cuboctahedra, corners with twelve equivalent Au(1)Cu4Au8 cuboctahedra, edges with eighteen equivalent Au(1)Cu4Au8 cuboctahedra, faces with eight equivalent Cu(1)Au12 cuboctahedra, and faces with twelve equivalent Au(1)Cu4Au8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_CuAu3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.639
_cell_length_b   5.639
_cell_length_c   4.704
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   129.529
_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
  Cu  Cu0  1  0.333  0.667  0.750  1.0
  Cu  Cu1  1  0.667  0.333  0.250  1.0
  Au  Au2  1  0.169  0.339  0.250  1.0
  Au  Au3  1  0.661  0.831  0.250  1.0
  Au  Au4  1  0.169  0.831  0.250  1.0
  Au  Au5  1  0.831  0.661  0.750  1.0
  Au  Au6  1  0.339  0.169  0.750  1.0
  Au  Au7  1  0.831  0.169  0.750  1.0
[/CIF]
.
The compound described by Au3Cu is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. Au(1) is bonded to eight equivalent Au(1) and four equivalent Cu(1) atoms to form distorted AuCu4Au8 cuboctahedra that share corners with four equivalent Cu(1)Au12 cuboctahedra, corners with fourteen equivalent Au(1)Cu4Au8 cuboctahedra, edges with six equivalent Cu(1)Au12 cuboctahedra, edges with twelve equivalent Au(1)Cu4Au8 cuboctahedra, faces with four equivalent Cu(1)Au12 cuboctahedra, and faces with sixteen equivalent Au(1)Cu4Au8 cuboctahedra. Cu(1) is bonded to twelve equivalent Au(1) atoms to form CuAu12 cuboctahedra that share corners with six equivalent Cu(1)Au12 cuboctahedra, corners with twelve equivalent Au(1)Cu4Au8 cuboctahedra, edges with eighteen equivalent Au(1)Cu4Au8 cuboctahedra, faces with eight equivalent Cu(1)Au12 cuboctahedra, and faces with twelve equivalent Au(1)Cu4Au8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_CuAu3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.639
_cell_length_b   5.639
_cell_length_c   4.704
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   129.529
_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
  Cu  Cu0  1  0.333  0.667  0.750  1.0
  Cu  Cu1  1  0.667  0.333  0.250  1.0
  Au  Au2  1  0.169  0.339  0.250  1.0
  Au  Au3  1  0.661  0.831  0.250  1.0
  Au  Au4  1  0.169  0.831  0.250  1.0
  Au  Au5  1  0.831  0.661  0.750  1.0
  Au  Au6  1  0.339  0.169  0.750  1.0
  Au  Au7  1  0.831  0.169  0.750  1.0
[/CIF]
.