data_Si3Ir
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.16
_cell_length_b   4.16
_cell_length_c   5.59
_cell_angle_alpha   107.59
_cell_angle_beta   107.59
_cell_angle_gamma   41.29
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Ir
_chemical_formula_sum   'Si3 Ir1'
_cell_volume   60.3
_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  0.0  0.0  0.0  1.0
  Si  Si2  1  0.23  0.0  0.51  1.0
  Si  Si3  1  0.74  0.0  0.77  1.0
  Ir  Ir0  1  0.99  0.0  0.64  1.0

data_Si3Ir
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.93
_cell_length_b   4.16
_cell_length_c   5.59
_cell_angle_alpha   107.59
_cell_angle_beta   90.0
_cell_angle_gamma   110.64
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si3Ir
_chemical_formula_sum   'Si3 Ir1'
_cell_volume   60.3
_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  0.0  1.0
  Si  Si1  1  0.0  0.26  0.23  1.0
  Si  Si2  1  0.0  0.77  0.49  1.0
  Ir  Ir3  1  0.0  0.01  0.36  1.0

Si Si Si Ir
Si Si Si Ir 0 2 - o - 1 3 - o o 2 3 o o o 