data_ZrAlCu2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.84
_cell_length_b   2.84
_cell_length_c   9.68
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ZrAlCu2
_chemical_formula_sum   'Zr1 Al1 Cu2'
_cell_volume   67.77
_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
  Zr  Zr3  1  0.42  0.82  0.84  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.0  0.0  0.49  1.0
  Cu  Cu2  1  0.0  0.0  0.18  1.0

data_ZrAlCu2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.93
_cell_length_b   2.84
_cell_length_c   9.68
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   ZrAlCu2
_chemical_formula_sum   'Zr2 Al2 Cu4'
_cell_volume   135.54
_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
  Zr  Zr0  2  0.4  0.0  0.84  1.0
  Al  Al1  2  0.49  0.5  0.0  1.0
  Cu  Cu2  2  0.49  0.5  0.18  1.0
  Cu  Cu3  2  0.49  0.5  0.49  1.0

Zr Al Cu Cu
Zr Al Cu Cu 0 1 o o + 0 1 o + + 0 1 + + + 1 3 o o o 2 2 + + o 2 2 o + o 2 2 + o o 2 3 o o o 
AlCu2Zr crystallizes in the triclinic P1 space group. Zr(1) is bonded in a 2-coordinate geometry to two equivalent Cu(1) and two equivalent Al(1) atoms. There is one shorter (3.65 Å) and one longer (3.67 Å) Zr(1)-Cu(1) bond length. There is one shorter (2.13 Å) and one longer (2.18 Å) Zr(1)-Al(1) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 9-coordinate geometry to two equivalent Zr(1), one Cu(2), and six equivalent Cu(1) atoms. The Cu(1)-Cu(2) bond length is 2.99 Å. All Cu(1)-Cu(1) bond lengths are 2.84 Å. In the second Cu site, Cu(2) is bonded in a single-bond geometry to one Cu(1) and one Al(1) atom. The Cu(2)-Al(1) bond length is 1.79 Å. Al(1) is bonded in a 3-coordinate geometry to two equivalent Zr(1) and one Cu(2) atom.