The compound described by Mg14YCu crystallizes in the hexagonal P-6m2 space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4); four Mg(1,1); four equivalent Mg(3); and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Y2Mg10 cuboctahedra; corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with four Mg(1,1)Y2Mg10 cuboctahedra; edges with eight equivalent Mg(3)YMg10Cu cuboctahedra; faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Y(1)Mg12 cuboctahedra; faces with four Mg(1,1)Y2Mg10 cuboctahedra; and faces with ten Mg(3,3)YMg10Cu cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Y(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10Cu2 cuboctahedra; corners with eight Mg(1,1)Y2Mg10 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight equivalent Mg(3)YMg10Cu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(1)Y2Mg10 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with four equivalent Mg(2)Mg10Cu2 cuboctahedra; and faces with ten Mg(3,3)YMg10Cu cuboctahedra. In the third Mg site, Mg(1) is bonded to two equivalent Mg(4); four equivalent Mg(1); four Mg(3,3); and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Y2Mg10 cuboctahedra; corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with four equivalent Mg(1)Y2Mg10 cuboctahedra; edges with eight Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Y(1)Mg12 cuboctahedra; faces with four equivalent Mg(1)Y2Mg10 cuboctahedra; and faces with ten Mg(3,3)YMg10Cu cuboctahedra. In the fourth Mg site, Mg(3) is bonded to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four Mg(3,3); one Y(1); and one Cu(1) atom to form distorted MgYMg10Cu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)YMg10Cu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four Mg(1,1)Y2Mg10 cuboctahedra; edges with four Mg(3,3)YMg10Cu cuboctahedra;  a faceface with one Y(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with five Mg(1,1)Y2Mg10 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. In the fifth Mg site, Mg(3) is bonded to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four equivalent Mg(3); one Y(1); and one Cu(1) atom to form distorted MgYMg10Cu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)YMg10Cu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four Mg(1,1)Y2Mg10 cuboctahedra; edges with four equivalent Mg(3)YMg10Cu cuboctahedra;  a faceface with one Y(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with five Mg(1,1)Y2Mg10 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. In the sixth Mg site, Mg(4) is bonded to three Mg(1,1); three equivalent Mg(2); and six Mg(3,3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; corners with twelve Mg(3,3)YMg10Cu cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Y2Mg10 cuboctahedra; edges with six Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with three Mg(1,1)Y2Mg10 cuboctahedra; faces with three equivalent Y(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg12 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. Y(1) is bonded to six Mg(1,1) and six Mg(3,3) atoms to form YMg12 cuboctahedra that share corners with six equivalent Y(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Y2Mg10 cuboctahedra; edges with twelve Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six equivalent Mg(4)Mg12 cuboctahedra; faces with six Mg(1,1)Y2Mg10 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. Cu(1) is bonded to six equivalent Mg(2) and six Mg(3,3) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Y2Mg10 cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with twelve Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Y(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with six equivalent Mg(4)Mg12 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. is represented by the CIF file [CIF]
data_YMg14Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.406
_cell_length_b   6.406
_cell_length_c   10.240
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   363.879
_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
  Y  Y0  1  0.167  0.333  0.125  1.0
  Mg  Mg1  1  0.179  0.840  0.125  1.0
  Mg  Mg2  1  0.163  0.831  0.625  1.0
  Mg  Mg3  1  0.660  0.321  0.125  1.0
  Mg  Mg4  1  0.669  0.337  0.625  1.0
  Mg  Mg5  1  0.660  0.840  0.125  1.0
  Mg  Mg6  1  0.669  0.831  0.625  1.0
  Mg  Mg7  1  0.329  0.171  0.389  1.0
  Mg  Mg8  1  0.329  0.171  0.861  1.0
  Mg  Mg9  1  0.329  0.658  0.389  1.0
  Mg  Mg10  1  0.329  0.658  0.861  1.0
  Mg  Mg11  1  0.842  0.171  0.389  1.0
  Mg  Mg12  1  0.842  0.171  0.861  1.0
  Mg  Mg13  1  0.833  0.667  0.369  1.0
  Mg  Mg14  1  0.833  0.667  0.881  1.0
  Cu  Cu15  1  0.167  0.333  0.625  1.0
[/CIF]
.
The compound described by Mg14YCu crystallizes in the hexagonal P-6m2 space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4); four Mg(1,1); four equivalent Mg(3); and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Y2Mg10 cuboctahedra; corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with four Mg(1,1)Y2Mg10 cuboctahedra; edges with eight equivalent Mg(3)YMg10Cu cuboctahedra; faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Y(1)Mg12 cuboctahedra; faces with four Mg(1,1)Y2Mg10 cuboctahedra; and faces with ten Mg(3,3)YMg10Cu cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Y(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10Cu2 cuboctahedra; corners with eight Mg(1,1)Y2Mg10 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight equivalent Mg(3)YMg10Cu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(1)Y2Mg10 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with four equivalent Mg(2)Mg10Cu2 cuboctahedra; and faces with ten Mg(3,3)YMg10Cu cuboctahedra. In the third Mg site, Mg(1) is bonded to two equivalent Mg(4); four equivalent Mg(1); four Mg(3,3); and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Y2Mg10 cuboctahedra; corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with four equivalent Mg(1)Y2Mg10 cuboctahedra; edges with eight Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Y(1)Mg12 cuboctahedra; faces with four equivalent Mg(1)Y2Mg10 cuboctahedra; and faces with ten Mg(3,3)YMg10Cu cuboctahedra. In the fourth Mg site, Mg(3) is bonded to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four Mg(3,3); one Y(1); and one Cu(1) atom to form distorted MgYMg10Cu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)YMg10Cu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four Mg(1,1)Y2Mg10 cuboctahedra; edges with four Mg(3,3)YMg10Cu cuboctahedra;  a faceface with one Y(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with five Mg(1,1)Y2Mg10 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. In the fifth Mg site, Mg(3) is bonded to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four equivalent Mg(3); one Y(1); and one Cu(1) atom to form distorted MgYMg10Cu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)YMg10Cu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Y(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four Mg(1,1)Y2Mg10 cuboctahedra; edges with four equivalent Mg(3)YMg10Cu cuboctahedra;  a faceface with one Y(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with five Mg(1,1)Y2Mg10 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. In the sixth Mg site, Mg(4) is bonded to three Mg(1,1); three equivalent Mg(2); and six Mg(3,3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; corners with twelve Mg(3,3)YMg10Cu cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Y2Mg10 cuboctahedra; edges with six Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with three Mg(1,1)Y2Mg10 cuboctahedra; faces with three equivalent Y(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg12 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. Y(1) is bonded to six Mg(1,1) and six Mg(3,3) atoms to form YMg12 cuboctahedra that share corners with six equivalent Y(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Y2Mg10 cuboctahedra; edges with twelve Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six equivalent Mg(4)Mg12 cuboctahedra; faces with six Mg(1,1)Y2Mg10 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. Cu(1) is bonded to six equivalent Mg(2) and six Mg(3,3) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Y2Mg10 cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with twelve Mg(3,3)YMg10Cu cuboctahedra; faces with two equivalent Y(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with six equivalent Mg(4)Mg12 cuboctahedra; and faces with six Mg(3,3)YMg10Cu cuboctahedra. is represented by the CIF file [CIF]
data_YMg14Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.406
_cell_length_b   6.406
_cell_length_c   10.240
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   363.879
_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
  Y  Y0  1  0.167  0.333  0.125  1.0
  Mg  Mg1  1  0.179  0.840  0.125  1.0
  Mg  Mg2  1  0.163  0.831  0.625  1.0
  Mg  Mg3  1  0.660  0.321  0.125  1.0
  Mg  Mg4  1  0.669  0.337  0.625  1.0
  Mg  Mg5  1  0.660  0.840  0.125  1.0
  Mg  Mg6  1  0.669  0.831  0.625  1.0
  Mg  Mg7  1  0.329  0.171  0.389  1.0
  Mg  Mg8  1  0.329  0.171  0.861  1.0
  Mg  Mg9  1  0.329  0.658  0.389  1.0
  Mg  Mg10  1  0.329  0.658  0.861  1.0
  Mg  Mg11  1  0.842  0.171  0.389  1.0
  Mg  Mg12  1  0.842  0.171  0.861  1.0
  Mg  Mg13  1  0.833  0.667  0.369  1.0
  Mg  Mg14  1  0.833  0.667  0.881  1.0
  Cu  Cu15  1  0.167  0.333  0.625  1.0
[/CIF]
.