data_SmF3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.93
_cell_length_b   3.93
_cell_length_c   3.93
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SmF3
_chemical_formula_sum   'Sm1 F3'
_cell_volume   42.9
_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
  Sm  Sm3  1  0.78  0.78  0.78  1.0
  F  F0  1  0.17  0.17  0.17  1.0
  F  F1  1  0.0  0.0  0.0  1.0
  F  F2  1  0.39  0.39  0.39  1.0

data_SmF3
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.93
_cell_length_b   3.93
_cell_length_c   9.63
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SmF3
_chemical_formula_sum   'Sm3 F9'
_cell_volume   128.71
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Sm  Sm0  3  0.0  0.0  0.22  1.0
  F  F1  3  0.0  0.0  -0.0  1.0
  F  F2  3  0.0  0.0  0.61  1.0
  F  F3  3  0.0  0.0  0.83  1.0

Sm F F F
Sm F F F 0 2 + o + 0 2 o + + 0 2 + + o 0 2 + + + 0 3 o o + 0 3 o + o 0 3 + o o 0 1 o + + 0 1 + o + 0 1 + + o 1 2 o o o 1 3 o o o 1 3 o o - 1 3 - o o 1 3 o - o 2 3 o o - 2 3 o - o 2 3 - o o 
SmF3 crystallizes in the trigonal R3m space group. Sm(1) is bonded in a 10-coordinate geometry to three equivalent F(1), three equivalent F(3), and four equivalent F(2) atoms. All Sm(1)-F(1) bond lengths are 2.33 Å. All Sm(1)-F(3) bond lengths are 2.33 Å. There is one shorter (2.13 Å) and three longer (2.51 Å) Sm(1)-F(2) bond lengths. There are three inequivalent F sites. In the first F site, F(1) is bonded to three equivalent Sm(1) and one F(2) atom to form distorted corner-sharing FSm3F tetrahedra. The F(1)-F(2) bond length is 1.62 Å. In the second F site, F(2) is bonded in a 5-coordinate geometry to four equivalent Sm(1) and one F(1) atom. In the third F site, F(3) is bonded in a trigonal non-coplanar geometry to three equivalent Sm(1) atoms.