data_Ca2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.16
_cell_length_b   6.16
_cell_length_c   6.16
_cell_angle_alpha   111.98
_cell_angle_beta   111.98
_cell_angle_gamma   104.56
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2As
_chemical_formula_sum   'Ca4 As2'
_cell_volume   179.13
_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
  Ca  Ca2  1  0.55  0.89  0.0  1.0
  Ca  Ca3  1  0.89  0.55  0.77  1.0
  Ca  Ca4  1  1.0  0.55  0.0  1.0
  Ca  Ca5  1  0.45  0.89  0.77  1.0
  As  As0  1  0.0  0.0  0.65  1.0
  As  As1  1  0.0  0.0  0.88  1.0

data_Ca2As
_symmetry_space_group_name_H-M   P1
_cell_length_a   6.16
_cell_length_b   6.16
_cell_length_c   6.16
_cell_angle_alpha   104.56
_cell_angle_beta   111.98
_cell_angle_gamma   111.98
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2As
_chemical_formula_sum   'Ca4 As2'
_cell_volume   179.13
_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
  Ca  Ca0  1  -0.0  0.45  0.11  1.0
  Ca  Ca1  1  0.0  0.0  0.45  1.0
  Ca  Ca2  1  0.77  0.32  0.88  1.0
  Ca  Ca3  1  0.77  0.88  0.22  1.0
  As  As4  1  0.65  0.65  0.65  1.0
  As  As5  1  0.88  0.88  0.88  1.0

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