data_Mg7Cd
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.36
_cell_length_b   6.36
_cell_length_c   6.36
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg7Cd
_chemical_formula_sum   'Mg7 Cd1'
_cell_volume   181.99
_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  Mg1  1  0.25  0.25  0.5  1.0
  Mg  Mg2  1  0.25  0.5  0.25  1.0
  Mg  Mg3  1  0.0  0.25  0.25  1.0
  Mg  Mg4  1  0.5  0.25  0.25  1.0
  Mg  Mg5  1  0.25  0.0  0.25  1.0
  Mg  Mg6  1  0.25  0.25  0.0  1.0
  Mg  Mg7  1  0.0  0.0  0.0  1.0
  Cd  Cd0  1  0.5  0.5  0.5  1.0

data_Mg7Cd
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.36
_cell_length_b   6.36
_cell_length_c   15.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Mg7Cd
_chemical_formula_sum   'Mg21 Cd3'
_cell_volume   545.96
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  9  0.08  0.17  0.67  1.0
  Mg  Mg1  9  0.17  0.08  0.83  1.0
  Mg  Mg2  3  0.0  0.0  -0.0  1.0
  Cd  Cd3  3  0.0  0.0  0.5  1.0

Mg Mg Mg Mg Mg Mg Mg Cd
Mg Mg Mg Mg Mg Mg Mg Cd 0 3 o o o 0 1 o o o 0 6 o o + 0 7 o o o 1 3 o o o 1 6 o + o 1 7 o o o 2 4 o o o 2 5 o o o 2 6 o o o 2 7 - o o 3 6 + o o 3 7 o o o 4 5 o o o 4 6 o o o 4 7 o - o 5 6 o o o 5 7 o o - 
Mg7Cd crystallizes in the trigonal R3m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to one Mg(3), two equivalent Mg(1), three equivalent Mg(2), and one Cd(1) atom. The Mg(1)-Mg(3) bond length is 2.76 Å. Both Mg(1)-Mg(1) bond lengths are 1.58 Å. There are two shorter (2.74 Å) and one longer (3.19 Å) Mg(1)-Mg(2) bond length. The Mg(1)-Cd(1) bond length is 2.74 Å. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Mg(3), two equivalent Mg(2), three equivalent Mg(1), and one Cd(1) atom. The Mg(2)-Mg(3) bond length is 2.74 Å. Both Mg(2)-Mg(2) bond lengths are 1.58 Å. The Mg(2)-Cd(1) bond length is 2.76 Å. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to three equivalent Mg(1) and three equivalent Mg(2) atoms. Cd(1) is bonded in a 6-coordinate geometry to three equivalent Mg(1) and three equivalent Mg(2) atoms.