The compound described by La4SiI5 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to one Si(1), two equivalent I(2), and three equivalent I(1) atoms to form LaSiI5 octahedra that share  a cornercorner with one La(2)Si2I4 octahedra,  a cornercorner with one La(1)SiI5 octahedra, edges with four equivalent La(2)Si2I4 octahedra, and edges with four equivalent La(1)SiI5 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the second La site, La(2) is bonded to two equivalent Si(1), one I(1), one I(2), and two equivalent I(3) atoms to form LaSi2I4 octahedra that share  a cornercorner with one La(1)SiI5 octahedra, corners with four equivalent La(2)Si2I4 octahedra, edges with four equivalent La(2)Si2I4 octahedra, and edges with four equivalent La(1)SiI5 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. Si(1) is bonded to two equivalent La(1) and four equivalent La(2) atoms to form edge-sharing SiLa6 octahedra. There are three inequivalent I sites. In the first I site, I(1) is bonded in a rectangular see-saw-like geometry to one La(2) and three equivalent La(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one La(2) and two equivalent La(1) atoms. In the third I site, I(3) is bonded in a square co-planar geometry to four equivalent La(2) atoms. is represented by the CIF file [CIF]
data_La4SiI5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.197
_cell_length_b   10.197
_cell_length_c   9.196
_cell_angle_alpha   77.473
_cell_angle_beta   77.473
_cell_angle_gamma   25.016
_symmetry_Int_Tables_number   1
_cell_volume   394.224
_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
  La  La0  1  0.851  0.851  0.076  1.0
  La  La1  1  0.149  0.149  0.924  1.0
  La  La2  1  0.500  0.500  0.217  1.0
  La  La3  1  0.500  0.500  0.783  1.0
  Si  Si4  1  0.000  0.000  0.000  1.0
  I  I5  1  0.672  0.672  0.176  1.0
  I  I6  1  0.328  0.328  0.824  1.0
  I  I7  1  0.668  0.668  0.659  1.0
  I  I8  1  0.332  0.332  0.341  1.0
  I  I9  1  0.000  0.000  0.500  1.0
[/CIF]
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The compound described by La4SiI5 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to one Si(1), two equivalent I(2), and three equivalent I(1) atoms to form LaSiI5 octahedra that share  a cornercorner with one La(2)Si2I4 octahedra,  a cornercorner with one La(1)SiI5 octahedra, edges with four equivalent La(2)Si2I4 octahedra, and edges with four equivalent La(1)SiI5 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the second La site, La(2) is bonded to two equivalent Si(1), one I(1), one I(2), and two equivalent I(3) atoms to form LaSi2I4 octahedra that share  a cornercorner with one La(1)SiI5 octahedra, corners with four equivalent La(2)Si2I4 octahedra, edges with four equivalent La(2)Si2I4 octahedra, and edges with four equivalent La(1)SiI5 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. Si(1) is bonded to two equivalent La(1) and four equivalent La(2) atoms to form edge-sharing SiLa6 octahedra. There are three inequivalent I sites. In the first I site, I(1) is bonded in a rectangular see-saw-like geometry to one La(2) and three equivalent La(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one La(2) and two equivalent La(1) atoms. In the third I site, I(3) is bonded in a square co-planar geometry to four equivalent La(2) atoms. is represented by the CIF file [CIF]
data_La4SiI5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.197
_cell_length_b   10.197
_cell_length_c   9.196
_cell_angle_alpha   77.473
_cell_angle_beta   77.473
_cell_angle_gamma   25.016
_symmetry_Int_Tables_number   1
_cell_volume   394.224
_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
  La  La0  1  0.851  0.851  0.076  1.0
  La  La1  1  0.149  0.149  0.924  1.0
  La  La2  1  0.500  0.500  0.217  1.0
  La  La3  1  0.500  0.500  0.783  1.0
  Si  Si4  1  0.000  0.000  0.000  1.0
  I  I5  1  0.672  0.672  0.176  1.0
  I  I6  1  0.328  0.328  0.824  1.0
  I  I7  1  0.668  0.668  0.659  1.0
  I  I8  1  0.332  0.332  0.341  1.0
  I  I9  1  0.000  0.000  0.500  1.0
[/CIF]
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