The compound described by Mg6CrCu crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Cr(1), and two equivalent Cu(1) atoms to form distorted MgMg8Cr2Cu2 cuboctahedra that share corners with four equivalent Cr(1)Mg10Cu2 cuboctahedra, corners with four equivalent Cu(1)Mg10Cr2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Cr(1), and two equivalent Cu(1) atoms to form distorted MgMg8Cr2Cu2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with four equivalent Mg(3)Mg10Cu2 cuboctahedra, corners with ten equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with two equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with two equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with four equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with six equivalent Mg(3)Mg10Cu2 cuboctahedra, corners with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Cu(1)Mg10Cr2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Cr(1)Mg10Cu2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cr(1) atoms to form distorted MgMg10Cr2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Cu2 cuboctahedra, corners with six equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Cu(1)Mg10Cr2 cuboctahedra. Cr(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cu(1) atoms to form CrMg10Cu2 cuboctahedra that share corners with four equivalent Cu(1)Mg10Cr2 cuboctahedra, corners with six equivalent Cr(1)Mg10Cu2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Mg(3)Mg10Cu2 cuboctahedra. Cu(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cr(1) atoms to form CuMg10Cr2 cuboctahedra that share corners with four equivalent Cr(1)Mg10Cu2 cuboctahedra, corners with six equivalent Cu(1)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Cr2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6CrCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.907
_cell_length_b   6.093
_cell_length_c   6.093
_cell_angle_alpha   119.585
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   158.420
_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
  Cr  Cr0  1  0.500  0.667  0.333  1.0
  Cu  Cu1  1  0.500  0.167  0.833  1.0
  Mg  Mg2  1  0.500  0.668  0.835  1.0
  Mg  Mg3  1  0.500  0.165  0.332  1.0
  Mg  Mg4  1  1.000  0.838  0.664  1.0
  Mg  Mg5  1  1.000  0.336  0.162  1.0
  Mg  Mg6  1  0.000  0.329  0.671  1.0
  Mg  Mg7  1  0.000  0.830  0.170  1.0
[/CIF]
.
The compound described by Mg6CrCu crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Cr(1), and two equivalent Cu(1) atoms to form distorted MgMg8Cr2Cu2 cuboctahedra that share corners with four equivalent Cr(1)Mg10Cu2 cuboctahedra, corners with four equivalent Cu(1)Mg10Cr2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Cr(1), and two equivalent Cu(1) atoms to form distorted MgMg8Cr2Cu2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with four equivalent Mg(3)Mg10Cu2 cuboctahedra, corners with ten equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with two equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with two equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with four equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with six equivalent Mg(3)Mg10Cu2 cuboctahedra, corners with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Cu(1)Mg10Cr2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Cr(1)Mg10Cu2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cr(1) atoms to form distorted MgMg10Cr2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Cu2 cuboctahedra, corners with six equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, edges with four equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Cu(1)Mg10Cr2 cuboctahedra. Cr(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cu(1) atoms to form CrMg10Cu2 cuboctahedra that share corners with four equivalent Cu(1)Mg10Cr2 cuboctahedra, corners with six equivalent Cr(1)Mg10Cu2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Mg(3)Mg10Cu2 cuboctahedra. Cu(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Cr(1) atoms to form CuMg10Cr2 cuboctahedra that share corners with four equivalent Cr(1)Mg10Cu2 cuboctahedra, corners with six equivalent Cu(1)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with two equivalent Cr(1)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(3)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, faces with two equivalent Mg(3)Mg10Cu2 cuboctahedra, faces with two equivalent Cr(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10Cr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Cr2Cu2 cuboctahedra, faces with four equivalent Mg(2)Mg8Cr2Cu2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Cr2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6CrCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.907
_cell_length_b   6.093
_cell_length_c   6.093
_cell_angle_alpha   119.585
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   158.420
_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
  Cr  Cr0  1  0.500  0.667  0.333  1.0
  Cu  Cu1  1  0.500  0.167  0.833  1.0
  Mg  Mg2  1  0.500  0.668  0.835  1.0
  Mg  Mg3  1  0.500  0.165  0.332  1.0
  Mg  Mg4  1  1.000  0.838  0.664  1.0
  Mg  Mg5  1  1.000  0.336  0.162  1.0
  Mg  Mg6  1  0.000  0.329  0.671  1.0
  Mg  Mg7  1  0.000  0.830  0.170  1.0
[/CIF]
.