The material structure described by Mg7Cu crystallizes in the hexagonal P-6m2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(3); four Mg(1,1); four Mg(2,2); and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Mg10Cu2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four Mg(1,1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight Mg(2,2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; and faces with ten Mg(2,2)Mg10Cu2 cuboctahedra. In the second Mg site, Mg(1) is bonded to two equivalent Mg(3), 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 Cu(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Mg10Cu2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; and faces with ten Mg(2,2)Mg10Cu2 cuboctahedra. In the third Mg site, Mg(2) is bonded to two equivalent Mg(3), 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(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Mg10Cu2 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four equivalent Cu(1)Mg12 cuboctahedra; edges with eight equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with ten Mg(1,1)Mg10Cu2 cuboctahedra. In the fourth Mg site, Mg(2) is bonded to two equivalent Mg(3); four Mg(1,1); four Mg(2,2); and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Mg10Cu2 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four Mg(2,2)Mg10Cu2 cuboctahedra; edges with four equivalent Cu(1)Mg12 cuboctahedra; edges with eight Mg(1,1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with ten Mg(1,1)Mg10Cu2 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(3)Mg12 cuboctahedra; corners with twelve Mg(2,2)Mg10Cu2 cuboctahedra; edges with six Mg(2,2)Mg10Cu2 cuboctahedra; edges with twelve Mg(1,1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with six equivalent Cu(1)Mg12 cuboctahedra. Cu(1) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Mg10Cu2 cuboctahedra; edges with twelve Mg(2,2)Mg10Cu2 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with six equivalent Mg(3)Mg12 cuboctahedra. is represented by the CIF card [CIF]
data_Mg7Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.197
_cell_length_b   6.197
_cell_length_c   5.011
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   166.629
_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
  Mg  Mg0  1  0.166  0.332  0.000  1.0
  Mg  Mg1  1  0.166  0.834  0.000  1.0
  Mg  Mg2  1  0.668  0.834  0.000  1.0
  Mg  Mg3  1  0.990  0.495  0.500  1.0
  Mg  Mg4  1  0.505  0.495  0.500  1.0
  Mg  Mg5  1  0.505  0.010  0.500  1.0
  Mg  Mg6  1  0.000  0.000  0.500  1.0
  Cu  Cu7  1  0.667  0.333  0.000  1.0
[/CIF]
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The material structure described by Mg7Cu crystallizes in the hexagonal P-6m2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(3); four Mg(1,1); four Mg(2,2); and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Mg10Cu2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four Mg(1,1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight Mg(2,2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; and faces with ten Mg(2,2)Mg10Cu2 cuboctahedra. In the second Mg site, Mg(1) is bonded to two equivalent Mg(3), 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 Cu(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Mg10Cu2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; and faces with ten Mg(2,2)Mg10Cu2 cuboctahedra. In the third Mg site, Mg(2) is bonded to two equivalent Mg(3), 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(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Mg10Cu2 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four equivalent Cu(1)Mg12 cuboctahedra; edges with eight equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with ten Mg(1,1)Mg10Cu2 cuboctahedra. In the fourth Mg site, Mg(2) is bonded to two equivalent Mg(3); four Mg(1,1); four Mg(2,2); and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Mg10Cu2 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four Mg(2,2)Mg10Cu2 cuboctahedra; edges with four equivalent Cu(1)Mg12 cuboctahedra; edges with eight Mg(1,1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with ten Mg(1,1)Mg10Cu2 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(3)Mg12 cuboctahedra; corners with twelve Mg(2,2)Mg10Cu2 cuboctahedra; edges with six Mg(2,2)Mg10Cu2 cuboctahedra; edges with twelve Mg(1,1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with six equivalent Cu(1)Mg12 cuboctahedra. Cu(1) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Mg10Cu2 cuboctahedra; edges with twelve Mg(2,2)Mg10Cu2 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Cu2 cuboctahedra; faces with six Mg(2,2)Mg10Cu2 cuboctahedra; and faces with six equivalent Mg(3)Mg12 cuboctahedra. is represented by the CIF card [CIF]
data_Mg7Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.197
_cell_length_b   6.197
_cell_length_c   5.011
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   166.629
_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
  Mg  Mg0  1  0.166  0.332  0.000  1.0
  Mg  Mg1  1  0.166  0.834  0.000  1.0
  Mg  Mg2  1  0.668  0.834  0.000  1.0
  Mg  Mg3  1  0.990  0.495  0.500  1.0
  Mg  Mg4  1  0.505  0.495  0.500  1.0
  Mg  Mg5  1  0.505  0.010  0.500  1.0
  Mg  Mg6  1  0.000  0.000  0.500  1.0
  Cu  Cu7  1  0.667  0.333  0.000  1.0
[/CIF]
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