The material described by MgLa2I8 crystallizes in the monoclinic C2/c space group. Mg(1) is bonded to two equivalent I(2), two equivalent I(3), and two equivalent I(4) atoms to form MgI6 octahedra that share corners with two equivalent La(1)I7 pentagonal bipyramids and edges with four equivalent La(1)I7 pentagonal bipyramids. La(1) is bonded to one I(3), two equivalent I(1), two equivalent I(2), and two equivalent I(4) atoms to form distorted LaI7 pentagonal bipyramids that share  a cornercorner with one Mg(1)I6 octahedra, edges with two equivalent Mg(1)I6 octahedra, and edges with three equivalent La(1)I7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 52°. There are four inequivalent I sites. In the first I site, I(1) is bonded in a water-like geometry to two equivalent La(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent La(1) atoms. In the third I site, I(3) is bonded in a water-like geometry to one Mg(1) and one La(1) atom. In the fourth I site, I(4) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent La(1) atoms. is represented by the CIF file [CIF]
data_La2MgI8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.463
_cell_length_b   9.463
_cell_length_c   13.542
_cell_angle_alpha   69.020
_cell_angle_beta   69.020
_cell_angle_gamma   61.570
_symmetry_Int_Tables_number   1
_cell_volume   969.389
_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
  La  La0  1  0.563  0.983  0.190  1.0
  La  La1  1  0.983  0.563  0.690  1.0
  La  La2  1  0.017  0.437  0.310  1.0
  La  La3  1  0.437  0.017  0.810  1.0
  Mg  Mg4  1  0.009  0.991  0.250  1.0
  Mg  Mg5  1  0.991  0.009  0.750  1.0
  I  I6  1  0.626  0.634  0.362  1.0
  I  I7  1  0.199  0.039  0.375  1.0
  I  I8  1  0.929  0.334  0.149  1.0
  I  I9  1  0.344  0.896  0.094  1.0
  I  I10  1  0.634  0.626  0.862  1.0
  I  I11  1  0.039  0.199  0.875  1.0
  I  I12  1  0.334  0.929  0.649  1.0
  I  I13  1  0.896  0.344  0.594  1.0
  I  I14  1  0.104  0.656  0.406  1.0
  I  I15  1  0.666  0.071  0.351  1.0
  I  I16  1  0.961  0.801  0.125  1.0
  I  I17  1  0.366  0.374  0.138  1.0
  I  I18  1  0.656  0.104  0.906  1.0
  I  I19  1  0.071  0.666  0.851  1.0
  I  I20  1  0.801  0.961  0.625  1.0
  I  I21  1  0.374  0.366  0.638  1.0
[/CIF]
.
The material described by MgLa2I8 crystallizes in the monoclinic C2/c space group. Mg(1) is bonded to two equivalent I(2), two equivalent I(3), and two equivalent I(4) atoms to form MgI6 octahedra that share corners with two equivalent La(1)I7 pentagonal bipyramids and edges with four equivalent La(1)I7 pentagonal bipyramids. La(1) is bonded to one I(3), two equivalent I(1), two equivalent I(2), and two equivalent I(4) atoms to form distorted LaI7 pentagonal bipyramids that share  a cornercorner with one Mg(1)I6 octahedra, edges with two equivalent Mg(1)I6 octahedra, and edges with three equivalent La(1)I7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 52°. There are four inequivalent I sites. In the first I site, I(1) is bonded in a water-like geometry to two equivalent La(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent La(1) atoms. In the third I site, I(3) is bonded in a water-like geometry to one Mg(1) and one La(1) atom. In the fourth I site, I(4) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent La(1) atoms. is represented by the CIF file [CIF]
data_La2MgI8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.463
_cell_length_b   9.463
_cell_length_c   13.542
_cell_angle_alpha   69.020
_cell_angle_beta   69.020
_cell_angle_gamma   61.570
_symmetry_Int_Tables_number   1
_cell_volume   969.389
_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
  La  La0  1  0.563  0.983  0.190  1.0
  La  La1  1  0.983  0.563  0.690  1.0
  La  La2  1  0.017  0.437  0.310  1.0
  La  La3  1  0.437  0.017  0.810  1.0
  Mg  Mg4  1  0.009  0.991  0.250  1.0
  Mg  Mg5  1  0.991  0.009  0.750  1.0
  I  I6  1  0.626  0.634  0.362  1.0
  I  I7  1  0.199  0.039  0.375  1.0
  I  I8  1  0.929  0.334  0.149  1.0
  I  I9  1  0.344  0.896  0.094  1.0
  I  I10  1  0.634  0.626  0.862  1.0
  I  I11  1  0.039  0.199  0.875  1.0
  I  I12  1  0.334  0.929  0.649  1.0
  I  I13  1  0.896  0.344  0.594  1.0
  I  I14  1  0.104  0.656  0.406  1.0
  I  I15  1  0.666  0.071  0.351  1.0
  I  I16  1  0.961  0.801  0.125  1.0
  I  I17  1  0.366  0.374  0.138  1.0
  I  I18  1  0.656  0.104  0.906  1.0
  I  I19  1  0.071  0.666  0.851  1.0
  I  I20  1  0.801  0.961  0.625  1.0
  I  I21  1  0.374  0.366  0.638  1.0
[/CIF]
.