data_FeAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.72
_cell_length_b   2.72
_cell_length_c   9.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   102.51
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeAs
_chemical_formula_sum   'Fe2 As2'
_cell_volume   66.03
_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
  Fe  Fe2  1  0.7  0.06  0.48  1.0
  Fe  Fe3  1  0.7  0.94  0.66  1.0
  As  As0  1  0.7  0.06  0.81  1.0
  As  As1  1  0.7  0.94  0.33  1.0

data_FeAs
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.72
_cell_length_b   2.72
_cell_length_c   9.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   102.51
_symmetry_Int_Tables_number   2
_chemical_formula_structural   FeAs
_chemical_formula_sum   'Fe2 As2'
_cell_volume   66.03
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Fe  Fe0  2  0.5  0.06  0.41  1.0
  As  As1  2  0.5  0.06  0.74  1.0

Fe Fe As As
Fe Fe As As 0 3 o - o 0 1 o - o 1 2 o + o 