data_SiF3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.8
_cell_length_b   5.8
_cell_length_c   2.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiF3
_chemical_formula_sum   'Si2 F6'
_cell_volume   82.82
_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  Si6  1  0.0  0.35  0.71  1.0
  Si  Si7  1  0.9  0.68  0.13  1.0
  F  F0  1  0.0  0.05  0.13  1.0
  F  F1  1  0.13  0.0  0.13  1.0
  F  F2  1  0.87  0.0  0.13  1.0
  F  F3  1  0.9  0.98  0.71  1.0
  F  F4  1  0.77  0.02  0.71  1.0
  F  F5  1  0.03  0.02  0.71  1.0

data_SiF3
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.84
_cell_length_b   5.8
_cell_length_c   5.8
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   SiF3
_chemical_formula_sum   'Si2 F6'
_cell_volume   82.82
_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  0.29  0.55  0.34  1.0
  F  F1  2  0.29  0.32  0.01  1.0
  F  F2  2  0.29  0.45  0.97  1.0
  F  F3  2  0.29  0.58  0.01  1.0

Si Si F F F F F F
Si Si F F F F F F 0 6 - o o 0 2 o o + 0 7 o o o 0 4 - o + 0 5 - - o 1 7 + + - 1 5 o o - 1 2 + + o 1 4 o + o 1 3 + + o 2 4 - o o 2 3 o o o 5 7 + + o 5 6 o + o 
SiF3 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two SiF3 clusters. Si(1) is bonded in a distorted single-bond geometry to one F(2) atom. The Si(1)-F(2) bond length is 1.68 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 1-coordinate geometry to one F(2) and one F(3) atom. The F(1)-F(2) bond length is 0.91 Å. The F(1)-F(3) bond length is 0.66 Å. In the second F site, F(2) is bonded in a distorted L-shaped geometry to one Si(1) and one F(1) atom. In the third F site, F(3) is bonded in a single-bond geometry to one F(1) atom.