The material structure described by Rb2CdI4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to one I(1), one I(3), and four equivalent I(2) atoms to form distorted RbI6 pentagonal pyramids that share corners with four equivalent Rb(2)I6 pentagonal pyramids, corners with two equivalent Cd(1)I4 tetrahedra, edges with two equivalent Rb(1)I6 pentagonal pyramids, edges with two equivalent Cd(1)I4 tetrahedra, and faces with two equivalent Rb(2)I6 pentagonal pyramids. In the second Rb site, Rb(2) is bonded to one I(1), one I(3), and four equivalent I(2) atoms to form distorted RbI6 pentagonal pyramids that share corners with four equivalent Rb(1)I6 pentagonal pyramids, corners with four equivalent Cd(1)I4 tetrahedra, edges with two equivalent Rb(2)I6 pentagonal pyramids,  an edgeedge with one Cd(1)I4 tetrahedra, and faces with two equivalent Rb(1)I6 pentagonal pyramids. Cd(1) is bonded to one I(1), one I(3), and two equivalent I(2) atoms to form CdI4 tetrahedra that share corners with two equivalent Rb(1)I6 pentagonal pyramids, corners with four equivalent Rb(2)I6 pentagonal pyramids,  an edgeedge with one Rb(2)I6 pentagonal pyramid, and edges with two equivalent Rb(1)I6 pentagonal pyramids. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to one Rb(1), one Rb(2), and one Cd(1) atom. In the second I site, I(2) is bonded to two equivalent Rb(1), two equivalent Rb(2), and one Cd(1) atom to form a mixture of distorted face, corner, and edge-sharing IRb4Cd square pyramids. In the third I site, I(3) is bonded in a distorted T-shaped geometry to one Rb(1), one Rb(2), and one Cd(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb2CdI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.216
_cell_length_b   8.410
_cell_length_c   10.159
_cell_angle_alpha   90.000
_cell_angle_beta   108.399
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   666.093
_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
  Rb  Rb0  1  0.216  0.250  0.552  1.0
  Rb  Rb1  1  0.784  0.750  0.448  1.0
  Rb  Rb2  1  0.257  0.250  0.066  1.0
  Rb  Rb3  1  0.743  0.750  0.934  1.0
  Cd  Cd4  1  0.775  0.250  0.700  1.0
  Cd  Cd5  1  0.225  0.750  0.300  1.0
  I  I6  1  0.589  0.250  0.417  1.0
  I  I7  1  0.411  0.750  0.583  1.0
  I  I8  1  0.993  0.007  0.239  1.0
  I  I9  1  0.007  0.993  0.761  1.0
  I  I10  1  0.007  0.507  0.761  1.0
  I  I11  1  0.993  0.493  0.239  1.0
  I  I12  1  0.578  0.250  0.879  1.0
  I  I13  1  0.422  0.750  0.121  1.0
[/CIF]
.
The material structure described by Rb2CdI4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to one I(1), one I(3), and four equivalent I(2) atoms to form distorted RbI6 pentagonal pyramids that share corners with four equivalent Rb(2)I6 pentagonal pyramids, corners with two equivalent Cd(1)I4 tetrahedra, edges with two equivalent Rb(1)I6 pentagonal pyramids, edges with two equivalent Cd(1)I4 tetrahedra, and faces with two equivalent Rb(2)I6 pentagonal pyramids. In the second Rb site, Rb(2) is bonded to one I(1), one I(3), and four equivalent I(2) atoms to form distorted RbI6 pentagonal pyramids that share corners with four equivalent Rb(1)I6 pentagonal pyramids, corners with four equivalent Cd(1)I4 tetrahedra, edges with two equivalent Rb(2)I6 pentagonal pyramids,  an edgeedge with one Cd(1)I4 tetrahedra, and faces with two equivalent Rb(1)I6 pentagonal pyramids. Cd(1) is bonded to one I(1), one I(3), and two equivalent I(2) atoms to form CdI4 tetrahedra that share corners with two equivalent Rb(1)I6 pentagonal pyramids, corners with four equivalent Rb(2)I6 pentagonal pyramids,  an edgeedge with one Rb(2)I6 pentagonal pyramid, and edges with two equivalent Rb(1)I6 pentagonal pyramids. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to one Rb(1), one Rb(2), and one Cd(1) atom. In the second I site, I(2) is bonded to two equivalent Rb(1), two equivalent Rb(2), and one Cd(1) atom to form a mixture of distorted face, corner, and edge-sharing IRb4Cd square pyramids. In the third I site, I(3) is bonded in a distorted T-shaped geometry to one Rb(1), one Rb(2), and one Cd(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb2CdI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.216
_cell_length_b   8.410
_cell_length_c   10.159
_cell_angle_alpha   90.000
_cell_angle_beta   108.399
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   666.093
_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
  Rb  Rb0  1  0.216  0.250  0.552  1.0
  Rb  Rb1  1  0.784  0.750  0.448  1.0
  Rb  Rb2  1  0.257  0.250  0.066  1.0
  Rb  Rb3  1  0.743  0.750  0.934  1.0
  Cd  Cd4  1  0.775  0.250  0.700  1.0
  Cd  Cd5  1  0.225  0.750  0.300  1.0
  I  I6  1  0.589  0.250  0.417  1.0
  I  I7  1  0.411  0.750  0.583  1.0
  I  I8  1  0.993  0.007  0.239  1.0
  I  I9  1  0.007  0.993  0.761  1.0
  I  I10  1  0.007  0.507  0.761  1.0
  I  I11  1  0.993  0.493  0.239  1.0
  I  I12  1  0.578  0.250  0.879  1.0
  I  I13  1  0.422  0.750  0.121  1.0
[/CIF]
.