data_HfMg2Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.09
_cell_length_b   3.09
_cell_length_c   8.07
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfMg2Cu
_chemical_formula_sum   'Hf1 Mg2 Cu1'
_cell_volume   76.92
_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
  Hf  Hf1  1  0.54  0.54  0.73  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Mg  Mg3  1  0.54  0.54  0.36  1.0
  Cu  Cu0  1  0.0  0.0  0.02  1.0

data_HfMg2Cu
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.37
_cell_length_b   4.37
_cell_length_c   8.07
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   HfMg2Cu
_chemical_formula_sum   'Hf2 Mg4 Cu2'
_cell_volume   153.85
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Hf  Hf0  2  0.04  0.5  0.73  1.0
  Mg  Mg1  2  0.0  0.0  0.0  1.0
  Mg  Mg2  2  0.04  0.5  0.36  1.0
  Cu  Cu3  2  0.0  0.0  0.02  1.0

Hf Mg Mg Cu
Hf Mg Mg Cu 0 3 o o + 0 3 o + + 0 3 + o + 0 3 + + + 0 1 o o + 0 1 o + + 0 1 + o + 0 1 + + + 0 0 + o o 0 0 o + o 0 2 o o o 1 3 o o o 1 2 o o o 1 2 o - o 1 2 - o o 1 2 - - o 2 3 o o o 2 3 o + o 2 3 + o o 2 3 + + o 2 2 + o o 2 2 o + o 
Mg2HfCu crystallizes in the monoclinic Cm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a single-bond geometry to four equivalent Hf(1) and one Cu(1) atom. There are a spread of Mg(1)-Hf(1) bond distances ranging from 2.97-3.24 Å. The Mg(1)-Cu(1) bond length is 0.12 Å. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to four equivalent Mg(2), one Hf(1), and one Cu(1) atom. All Mg(2)-Mg(2) bond lengths are 3.09 Å. The Mg(2)-Hf(1) bond length is 3.01 Å. The Mg(2)-Cu(1) bond length is 3.38 Å. Hf(1) is bonded in a 9-coordinate geometry to one Mg(2), four equivalent Mg(1), and four equivalent Hf(1) atoms. All Hf(1)-Hf(1) bond lengths are 3.09 Å. Cu(1) is bonded in a single-bond geometry to one Mg(1) and one Mg(2) atom.