data_Si2AsCl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.95
_cell_length_b   5.95
_cell_length_c   5.95
_cell_angle_alpha   150.04
_cell_angle_beta   134.41
_cell_angle_gamma   55.52
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2AsCl
_chemical_formula_sum   'Si2 As1 Cl1'
_cell_volume   74.8
_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  Si2  1  0.54  0.0  0.0  1.0
  Si  Si3  1  0.0  0.31  0.27  1.0
  As  As0  1  0.0  0.0  0.27  1.0
  Cl  Cl1  1  0.0  0.0  0.0  1.0

data_Si2AsCl
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.08
_cell_length_b   4.61
_cell_length_c   5.95
_cell_angle_alpha   112.8
_cell_angle_beta   104.98
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2AsCl
_chemical_formula_sum   'Si2 As1 Cl1'
_cell_volume   74.8
_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  1  0.0  0.0  0.46  1.0
  Si  Si1  1  0.69  0.96  0.96  1.0
  As  As2  1  0.0  0.27  0.27  1.0
  Cl  Cl3  1  0.0  0.0  0.0  1.0

Si Si As Cl
Si Si As Cl 0 2 + o o 1 3 o o o 1 2 o o o 2 3 o o o 