data_Zn3Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.86
_cell_length_b   4.86
_cell_length_c   4.86
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Zn3Cu
_chemical_formula_sum   'Zn6 Cu2'
_cell_volume   115.12
_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
  Zn  Zn2  1  0.65  0.0  0.43  1.0
  Zn  Zn3  1  0.22  0.0  0.43  1.0
  Zn  Zn4  1  0.43  0.65  0.0  1.0
  Zn  Zn5  1  0.43  0.22  0.0  1.0
  Zn  Zn6  1  0.0  0.43  0.65  1.0
  Zn  Zn7  1  0.0  0.43  0.22  1.0
  Cu  Cu0  1  0.43  0.43  0.43  1.0
  Cu  Cu1  1  0.0  0.0  0.0  1.0

data_Zn3Cu
_symmetry_space_group_name_H-M   R3
_cell_length_a   6.88
_cell_length_b   6.88
_cell_length_c   8.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Zn3Cu
_chemical_formula_sum   'Zn18 Cu6'
_cell_volume   345.36
_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
  Zn  Zn0  9  0.0  0.78  0.22  1.0
  Zn  Zn1  9  0.07  0.36  0.36  1.0
  Cu  Cu2  3  0.0  0.0  0.0  1.0
  Cu  Cu3  3  0.0  0.0  0.43  1.0

Zn Zn Zn Zn Zn Zn Cu Cu
CuZn3 crystallizes in the trigonal R3 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 12-coordinate geometry to six equivalent Zn(1) and six equivalent Zn(2) atoms. There are three shorter (2.35 Å) and three longer (2.96 Å) Cu(1)-Zn(1) bond lengths. There are three shorter (2.35 Å) and three longer (2.96 Å) Cu(1)-Zn(2) bond lengths. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to three equivalent Zn(1) and six equivalent Zn(2) atoms. All Cu(2)-Zn(1) bond lengths are 2.71 Å. There are three shorter (2.35 Å) and three longer (2.96 Å) Cu(2)-Zn(2) bond lengths. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 3-coordinate geometry to one Cu(2), two equivalent Cu(1), and one Zn(2) atom. The Zn(1)-Zn(2) bond length is 2.10 Å. In the second Zn site, Zn(2) is bonded in a 3-coordinate geometry to two equivalent Cu(1), two equivalent Cu(2), and one Zn(1) atom.