data_AlF3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.2
_cell_length_b   6.2
_cell_length_c   2.56
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AlF3
_chemical_formula_sum   'Al2 F6'
_cell_volume   85.03
_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
  Al  Al0  1  0.1  0.79  0.92  1.0
  Al  Al1  1  0.0  0.58  0.64  1.0
  F  F2  1  0.0  0.25  0.92  1.0
  F  F3  1  0.85  0.24  0.92  1.0
  F  F4  1  0.15  0.24  0.92  1.0
  F  F5  1  0.95  0.13  0.64  1.0
  F  F6  1  0.25  0.13  0.64  1.0
  F  F7  1  0.1  0.12  0.64  1.0

data_AlF3
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.56
_cell_length_b   6.2
_cell_length_c   6.2
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   AlF3
_chemical_formula_sum   'Al2 F6'
_cell_volume   85.03
_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
  Al  Al0  2  0.36  0.95  0.39  1.0
  F  F1  2  0.36  0.05  0.93  1.0
  F  F2  2  0.36  0.2  0.94  1.0
  F  F3  2  0.36  0.9  0.94  1.0

Al Al F F F F F F
AlF3 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one AlF3 cluster. Al(1) is bonded in a 1-coordinate geometry to one F(1) and one F(2) atom. The Al(1)-F(1) bond length is 2.15 Å. The Al(1)-F(2) bond length is 1.94 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Al(1), one F(2), and two equivalent F(3) atoms. The F(1)-F(2) bond length is 0.90 Å. There is one shorter (0.96 Å) and one longer (0.98 Å) F(1)-F(3) bond length. In the second F site, F(2) is bonded in an L-shaped geometry to one Al(1) and one F(1) atom. In the third F site, F(3) is bonded in a distorted L-shaped geometry to two equivalent F(1) atoms.