The structure described by Cs2HgI4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one I(2), four equivalent I(1), and four equivalent I(3) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one I(3), three equivalent I(2), and four equivalent I(1) atoms. Hg(1) is bonded in a tetrahedral geometry to one I(2), one I(3), and two equivalent I(1) atoms. There are three inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Cs(1), two equivalent Cs(2), and one Hg(1) atom to form a mixture of distorted edge, corner, and face-sharing ICs4Hg square pyramids. In the second I site, I(2) is bonded to one Cs(1), three equivalent Cs(2), and one Hg(1) atom to form a mixture of distorted edge and corner-sharing ICs4Hg trigonal bipyramids. In the third I site, I(3) is bonded in a 6-coordinate geometry to one Cs(2), four equivalent Cs(1), and one Hg(1) atom. is represented by the CIF card [CIF]
data_Cs2HgI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.065
_cell_length_b   8.479
_cell_length_c   11.244
_cell_angle_alpha   90.000
_cell_angle_beta   112.424
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   710.846
_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
  Cs  Cs0  1  0.340  0.750  0.541  1.0
  Cs  Cs1  1  0.203  0.250  0.916  1.0
  Cs  Cs2  1  0.660  0.250  0.459  1.0
  Cs  Cs3  1  0.797  0.750  0.084  1.0
  Hg  Hg4  1  0.913  0.750  0.716  1.0
  Hg  Hg5  1  0.087  0.250  0.284  1.0
  I  I6  1  0.257  0.987  0.223  1.0
  I  I7  1  0.281  0.750  0.867  1.0
  I  I8  1  0.186  0.250  0.555  1.0
  I  I9  1  0.814  0.750  0.445  1.0
  I  I10  1  0.257  0.513  0.223  1.0
  I  I11  1  0.719  0.250  0.133  1.0
  I  I12  1  0.743  0.487  0.777  1.0
  I  I13  1  0.743  0.013  0.777  1.0
[/CIF]
.
The structure described by Cs2HgI4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one I(2), four equivalent I(1), and four equivalent I(3) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one I(3), three equivalent I(2), and four equivalent I(1) atoms. Hg(1) is bonded in a tetrahedral geometry to one I(2), one I(3), and two equivalent I(1) atoms. There are three inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Cs(1), two equivalent Cs(2), and one Hg(1) atom to form a mixture of distorted edge, corner, and face-sharing ICs4Hg square pyramids. In the second I site, I(2) is bonded to one Cs(1), three equivalent Cs(2), and one Hg(1) atom to form a mixture of distorted edge and corner-sharing ICs4Hg trigonal bipyramids. In the third I site, I(3) is bonded in a 6-coordinate geometry to one Cs(2), four equivalent Cs(1), and one Hg(1) atom. is represented by the CIF card [CIF]
data_Cs2HgI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.065
_cell_length_b   8.479
_cell_length_c   11.244
_cell_angle_alpha   90.000
_cell_angle_beta   112.424
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   710.846
_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
  Cs  Cs0  1  0.340  0.750  0.541  1.0
  Cs  Cs1  1  0.203  0.250  0.916  1.0
  Cs  Cs2  1  0.660  0.250  0.459  1.0
  Cs  Cs3  1  0.797  0.750  0.084  1.0
  Hg  Hg4  1  0.913  0.750  0.716  1.0
  Hg  Hg5  1  0.087  0.250  0.284  1.0
  I  I6  1  0.257  0.987  0.223  1.0
  I  I7  1  0.281  0.750  0.867  1.0
  I  I8  1  0.186  0.250  0.555  1.0
  I  I9  1  0.814  0.750  0.445  1.0
  I  I10  1  0.257  0.513  0.223  1.0
  I  I11  1  0.719  0.250  0.133  1.0
  I  I12  1  0.743  0.487  0.777  1.0
  I  I13  1  0.743  0.013  0.777  1.0
[/CIF]
.