The crystal structure described by Cu3Al is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to eight Cu(1,1) and four equivalent Al(1) atoms to form CuAl4Cu8 cuboctahedra that share corners with four equivalent Al(1)Cu12 cuboctahedra; corners with fourteen equivalent Cu(1)Al4Cu8 cuboctahedra; edges with six equivalent Al(1)Cu12 cuboctahedra; edges with twelve Cu(1,1)Al4Cu8 cuboctahedra; faces with four equivalent Al(1)Cu12 cuboctahedra; and faces with sixteen Cu(1,1)Al4Cu8 cuboctahedra. In the second Cu site, Cu(1) is bonded to eight equivalent Cu(1) and four equivalent Al(1) atoms to form CuAl4Cu8 cuboctahedra that share corners with four equivalent Al(1)Cu12 cuboctahedra; corners with fourteen Cu(1,1)Al4Cu8 cuboctahedra; edges with six equivalent Al(1)Cu12 cuboctahedra; edges with twelve equivalent Cu(1)Al4Cu8 cuboctahedra; faces with four equivalent Al(1)Cu12 cuboctahedra; and faces with sixteen Cu(1,1)Al4Cu8 cuboctahedra. Al(1) is bonded to twelve Cu(1,1) atoms to form AlCu12 cuboctahedra that share corners with six equivalent Al(1)Cu12 cuboctahedra; corners with twelve Cu(1,1)Al4Cu8 cuboctahedra; edges with eighteen Cu(1,1)Al4Cu8 cuboctahedra; faces with eight equivalent Al(1)Cu12 cuboctahedra; and faces with twelve Cu(1,1)Al4Cu8 cuboctahedra. is represented by the CIF card [CIF]
data_AlCu3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.138
_cell_length_b   5.138
_cell_length_c   4.206
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   96.159
_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
  Al  Al0  1  0.333  0.667  0.750  1.0
  Al  Al1  1  0.667  0.333  0.250  1.0
  Cu  Cu2  1  0.166  0.331  0.250  1.0
  Cu  Cu3  1  0.669  0.834  0.250  1.0
  Cu  Cu4  1  0.166  0.834  0.250  1.0
  Cu  Cu5  1  0.834  0.669  0.750  1.0
  Cu  Cu6  1  0.331  0.166  0.750  1.0
  Cu  Cu7  1  0.834  0.166  0.750  1.0
[/CIF]
.
The crystal structure described by Cu3Al is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to eight Cu(1,1) and four equivalent Al(1) atoms to form CuAl4Cu8 cuboctahedra that share corners with four equivalent Al(1)Cu12 cuboctahedra; corners with fourteen equivalent Cu(1)Al4Cu8 cuboctahedra; edges with six equivalent Al(1)Cu12 cuboctahedra; edges with twelve Cu(1,1)Al4Cu8 cuboctahedra; faces with four equivalent Al(1)Cu12 cuboctahedra; and faces with sixteen Cu(1,1)Al4Cu8 cuboctahedra. In the second Cu site, Cu(1) is bonded to eight equivalent Cu(1) and four equivalent Al(1) atoms to form CuAl4Cu8 cuboctahedra that share corners with four equivalent Al(1)Cu12 cuboctahedra; corners with fourteen Cu(1,1)Al4Cu8 cuboctahedra; edges with six equivalent Al(1)Cu12 cuboctahedra; edges with twelve equivalent Cu(1)Al4Cu8 cuboctahedra; faces with four equivalent Al(1)Cu12 cuboctahedra; and faces with sixteen Cu(1,1)Al4Cu8 cuboctahedra. Al(1) is bonded to twelve Cu(1,1) atoms to form AlCu12 cuboctahedra that share corners with six equivalent Al(1)Cu12 cuboctahedra; corners with twelve Cu(1,1)Al4Cu8 cuboctahedra; edges with eighteen Cu(1,1)Al4Cu8 cuboctahedra; faces with eight equivalent Al(1)Cu12 cuboctahedra; and faces with twelve Cu(1,1)Al4Cu8 cuboctahedra. is represented by the CIF card [CIF]
data_AlCu3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.138
_cell_length_b   5.138
_cell_length_c   4.206
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   96.159
_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
  Al  Al0  1  0.333  0.667  0.750  1.0
  Al  Al1  1  0.667  0.333  0.250  1.0
  Cu  Cu2  1  0.166  0.331  0.250  1.0
  Cu  Cu3  1  0.669  0.834  0.250  1.0
  Cu  Cu4  1  0.166  0.834  0.250  1.0
  Cu  Cu5  1  0.834  0.669  0.750  1.0
  Cu  Cu6  1  0.331  0.166  0.750  1.0
  Cu  Cu7  1  0.834  0.166  0.750  1.0
[/CIF]
.