data_Zr3Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.46
_cell_length_b   5.46
_cell_length_c   5.46
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Zr3Cu
_chemical_formula_sum   'Zr6 Cu2'
_cell_volume   162.64
_cell_formula_units_Z   2
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  Zr2  1  0.73  0.09  0.0  1.0
  Zr  Zr3  1  0.73  0.36  0.0  1.0
  Zr  Zr4  1  0.09  0.0  0.73  1.0
  Zr  Zr5  1  0.0  0.73  0.09  1.0
  Zr  Zr6  1  0.0  0.73  0.36  1.0
  Zr  Zr7  1  0.36  0.0  0.73  1.0
  Cu  Cu0  1  0.73  0.73  0.73  1.0
  Cu  Cu1  1  0.0  0.0  0.0  1.0

data_Zr3Cu
_symmetry_space_group_name_H-M   R3
_cell_length_a   7.72
_cell_length_b   7.72
_cell_length_c   9.45
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Zr3Cu
_chemical_formula_sum   'Zr18 Cu6'
_cell_volume   487.92
_cell_formula_units_Z   6
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  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+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
  Zr  Zr0  9  -0.0  0.64  0.36  1.0
  Zr  Zr1  9  0.06  0.85  0.94  1.0
  Cu  Cu2  3  0.0  0.0  0.0  1.0
  Cu  Cu3  3  0.0  0.0  0.73  1.0

Zr Zr Zr Zr Zr Zr Cu Cu
Zr3Cu crystallizes in the trigonal R3 space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a distorted single-bond geometry to one Zr(2), one Cu(1), and one Cu(2) atom. The Zr(1)-Zr(2) bond length is 1.48 Å. The Zr(1)-Cu(1) bond length is 2.48 Å. The Zr(1)-Cu(2) bond length is 1.56 Å. In the second Zr site, Zr(2) is bonded in a distorted bent 150 degrees geometry to one Zr(1) and one Cu(1) atom. The Zr(2)-Cu(1) bond length is 2.48 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 6-coordinate geometry to three equivalent Zr(1) and three equivalent Zr(2) atoms. In the second Cu site, Cu(2) is bonded in a trigonal non-coplanar geometry to three equivalent Zr(1) atoms.