data_NaCu2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.44
_cell_length_b   4.44
_cell_length_c   4.44
_cell_angle_alpha   121.58
_cell_angle_beta   118.57
_cell_angle_gamma   89.89
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCu2As
_chemical_formula_sum   'Na1 Cu2 As1'
_cell_volume   61.65
_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
  Na  Na3  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.0  0.27  0.46  1.0
  Cu  Cu2  1  0.17  0.0  0.68  1.0
  As  As0  1  0.0  0.0  0.14  1.0

data_NaCu2As
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.33
_cell_length_b   4.44
_cell_length_c   4.44
_cell_angle_alpha   61.43
_cell_angle_beta   60.79
_cell_angle_gamma   60.79
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCu2As
_chemical_formula_sum   'Na1 Cu2 As1'
_cell_volume   61.65
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.46  0.0  0.81  1.0
  Cu  Cu2  1  0.52  0.17  0.32  1.0
  As  As3  1  0.14  0.0  0.86  1.0

Na Cu Cu As
Na Cu Cu As 0 3 o o o 0 2 o o - 1 3 o o o 1 2 o o o 2 3 o o o 