data_[Si2As1P1O1]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  As  2.1800  1.1500  0.6600
  P  2.1900  1.0000  0.5500
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P4/mmm]
_cell_length_a [4.9159]
_cell_length_b [4.9159]
_cell_length_c [4.5304]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [123]
_chemical_formula_structural [Si2AsPO]
_chemical_formula_sum '[Si2 As1 P1 O1]'
_cell_volume [109.4816]
_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
[
  Si  Si0  2  0.0000  0.5000  0.0000  1
  As  As1  1  0.0000  0.0000  0.0000  1
  P  P2  1  0.0000  0.0000  0.5000  1
  O  O3  1  0.5000  0.5000  0.5000  1
]