data_Cu2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.3
_cell_length_b   4.3
_cell_length_c   5.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2As
_chemical_formula_sum   'Cu4 As2'
_cell_volume   84.75
_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
  Cu  Cu2  1  0.0  0.0  0.64  1.0
  Cu  Cu3  1  0.0  0.0  0.0  1.0
  Cu  Cu4  1  0.15  0.24  0.96  1.0
  Cu  Cu5  1  0.0  0.48  0.32  1.0
  As  As0  1  0.0  0.48  0.96  1.0
  As  As1  1  0.15  0.24  0.32  1.0

data_Cu2As
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.3
_cell_length_b   4.3
_cell_length_c   5.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2As
_chemical_formula_sum   'Cu4 As2'
_cell_volume   84.75
_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
  Cu  Cu0  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.0  0.0  0.64  1.0
  Cu  Cu2  1  0.0  0.48  0.32  1.0
  Cu  Cu3  1  0.15  0.24  0.96  1.0
  As  As4  1  0.0  0.48  0.96  1.0
  As  As5  1  0.15  0.24  0.32  1.0

Cu Cu Cu Cu As As
Cu Cu Cu Cu As As 0 5 o o o 0 1 o o + 0 2 o o o 1 2 o o - 2 4 o o o 3 5 o o o 