The crystal structure described by Ni6CuAl crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to eight equivalent Ni(3) and four equivalent Al(1) atoms to form NiAl4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Al4Ni8 cuboctahedra, corners with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with eight equivalent Cu(1)Ni12 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(1)Al4Ni8 cuboctahedra, faces with four equivalent Al(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to eight equivalent Ni(3) and four equivalent Cu(1) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(1)Al4Ni8 cuboctahedra, edges with eight equivalent Al(1)Ni12 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(1)Al4Ni8 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. In the third Ni site, Ni(3) is bonded to two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(3), two equivalent Cu(1), and two equivalent Al(1) atoms to form NiAl2Cu2Ni8 cuboctahedra that share corners with twelve equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(1)Al4Ni8 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Al(1)Ni12 cuboctahedra, edges with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(1)Al4Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with two equivalent Al(1)Ni12 cuboctahedra, and faces with ten equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. Cu(1) is bonded to four equivalent Ni(2) and eight equivalent Ni(3) atoms to form CuNi12 cuboctahedra that share corners with four equivalent Cu(1)Ni12 cuboctahedra, corners with eight equivalent Al(1)Ni12 cuboctahedra, edges with eight equivalent Ni(1)Al4Ni8 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Al(1)Ni12 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. Al(1) is bonded to four equivalent Ni(1) and eight equivalent Ni(3) atoms to form AlNi12 cuboctahedra that share corners with four equivalent Al(1)Ni12 cuboctahedra, corners with eight equivalent Cu(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with four equivalent Ni(1)Al4Ni8 cuboctahedra, faces with four equivalent Al(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. is represented by the CIF file [CIF]
data_AlCuNi6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.543
_cell_length_b   3.543
_cell_length_c   7.091
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   89.004
_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
  Al  Al0  1  0.000  0.000  0.000  1.0
  Cu  Cu1  1  0.000  0.000  0.500  1.0
  Ni  Ni2  1  0.500  0.500  0.000  1.0
  Ni  Ni3  1  0.500  0.500  0.500  1.0
  Ni  Ni4  1  0.500  0.000  0.251  1.0
  Ni  Ni5  1  0.500  0.000  0.749  1.0
  Ni  Ni6  1  0.000  0.500  0.251  1.0
  Ni  Ni7  1  0.000  0.500  0.749  1.0
[/CIF]
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The crystal structure described by Ni6CuAl crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to eight equivalent Ni(3) and four equivalent Al(1) atoms to form NiAl4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Al4Ni8 cuboctahedra, corners with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with eight equivalent Cu(1)Ni12 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(1)Al4Ni8 cuboctahedra, faces with four equivalent Al(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to eight equivalent Ni(3) and four equivalent Cu(1) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(1)Al4Ni8 cuboctahedra, edges with eight equivalent Al(1)Ni12 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(1)Al4Ni8 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. In the third Ni site, Ni(3) is bonded to two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(3), two equivalent Cu(1), and two equivalent Al(1) atoms to form NiAl2Cu2Ni8 cuboctahedra that share corners with twelve equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(1)Al4Ni8 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Al(1)Ni12 cuboctahedra, edges with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(1)Al4Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with two equivalent Al(1)Ni12 cuboctahedra, and faces with ten equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. Cu(1) is bonded to four equivalent Ni(2) and eight equivalent Ni(3) atoms to form CuNi12 cuboctahedra that share corners with four equivalent Cu(1)Ni12 cuboctahedra, corners with eight equivalent Al(1)Ni12 cuboctahedra, edges with eight equivalent Ni(1)Al4Ni8 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Al(1)Ni12 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. Al(1) is bonded to four equivalent Ni(1) and eight equivalent Ni(3) atoms to form AlNi12 cuboctahedra that share corners with four equivalent Al(1)Ni12 cuboctahedra, corners with eight equivalent Cu(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with sixteen equivalent Ni(3)Al2Cu2Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with four equivalent Ni(1)Al4Ni8 cuboctahedra, faces with four equivalent Al(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(3)Al2Cu2Ni8 cuboctahedra. is represented by the CIF file [CIF]
data_AlCuNi6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.543
_cell_length_b   3.543
_cell_length_c   7.091
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   89.004
_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
  Al  Al0  1  0.000  0.000  0.000  1.0
  Cu  Cu1  1  0.000  0.000  0.500  1.0
  Ni  Ni2  1  0.500  0.500  0.000  1.0
  Ni  Ni3  1  0.500  0.500  0.500  1.0
  Ni  Ni4  1  0.500  0.000  0.251  1.0
  Ni  Ni5  1  0.500  0.000  0.749  1.0
  Ni  Ni6  1  0.000  0.500  0.251  1.0
  Ni  Ni7  1  0.000  0.500  0.749  1.0
[/CIF]
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