data_Na2AsSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.35
_cell_length_b   5.35
_cell_length_c   3.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   110.28
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2AsSe
_chemical_formula_sum   'Na2 As1 Se1'
_cell_volume   85.19
_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  Na1  1  0.53  0.2  0.59  1.0
  Na  Na2  1  0.53  0.8  0.59  1.0
  As  As0  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.06  0.0  0.0  1.0

data_Na2AsSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.17
_cell_length_b   5.35
_cell_length_c   5.35
_cell_angle_alpha   110.28
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2AsSe
_chemical_formula_sum   'Na2 As1 Se1'
_cell_volume   85.19
_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  0.59  0.53  0.2  1.0
  Na  Na1  1  0.59  0.53  0.8  1.0
  As  As2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.0  0.06  0.0  1.0

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