data_Si2P
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.69
_cell_length_b   5.69
_cell_length_c   5.99
_cell_angle_alpha   121.47
_cell_angle_beta   121.47
_cell_angle_gamma   35.4
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2P
_chemical_formula_sum   'Si4 P2'
_cell_volume   94.15
_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
  Si  Si2  1  0.38  0.0  0.8  1.0
  Si  Si3  1  0.92  0.0  0.74  1.0
  Si  Si4  1  0.64  0.0  0.28  1.0
  Si  Si5  1  0.18  0.0  0.22  1.0
  P  P0  1  0.58  0.0  0.75  1.0
  P  P1  1  0.98  0.0  0.26  1.0

data_Si2P
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.46
_cell_length_b   5.69
_cell_length_c   5.72
_cell_angle_alpha   63.35
_cell_angle_beta   72.38
_cell_angle_gamma   72.3
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Si2P
_chemical_formula_sum   'Si4 P2'
_cell_volume   94.15
_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
  Si  Si0  2  0.0  0.09  0.27  1.0
  Si  Si1  2  0.0  0.31  0.79  1.0
  P  P2  2  0.0  0.44  0.26  1.0

Si Si Si Si P P