data_SiSnAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.21
_cell_length_b   6.91
_cell_length_c   3.28
_cell_angle_alpha   81.6
_cell_angle_beta   71.66
_cell_angle_gamma   26.74
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiSnAs
_chemical_formula_sum   'Si1 Sn1 As1'
_cell_volume   66.16
_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  Si1  1  0.82  0.73  0.65  1.0
  Sn  Sn2  1  0.82  0.73  0.34  1.0
  As  As0  1  0.82  0.73  0.35  1.0

data_SiSnAs
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.64
_cell_length_b   13.34
_cell_length_c   3.28
_cell_angle_alpha   90.0
_cell_angle_beta   123.72
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SiSnAs
_chemical_formula_sum   'Si2 Sn2 As2'
_cell_volume   132.32
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  0.23  0.5  0.53  1.0
  Sn  Sn1  2  0.23  0.5  0.84  1.0
  As  As2  2  0.23  0.5  0.83  1.0

Si Sn As