The material structure described by Cs2HgI4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one I(3), two equivalent I(1), two equivalent I(4), and three equivalent I(2) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one I(2), two equivalent I(1), two equivalent I(4), and three equivalent I(3) atoms. Hg(1) is bonded in a tetrahedral geometry to one I(1), one I(2), one I(3), and one I(4) atom. There are four inequivalent I sites. In the first I site, I(1) is bonded in a 5-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and one Hg(1) atom. In the second I site, I(2) is bonded in a 5-coordinate geometry to one Cs(2), three equivalent Cs(1), and one Hg(1) atom. In the third I site, I(3) is bonded in a 5-coordinate geometry to one Cs(1), three equivalent Cs(2), and one Hg(1) atom. In the fourth I site, I(4) is bonded to two equivalent Cs(1), two equivalent Cs(2), and one Hg(1) atom to form distorted corner-sharing ICs4Hg square pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cs2HgI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.657
_cell_length_b   8.121
_cell_length_c   11.394
_cell_angle_alpha   68.468
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   745.157
_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  0.744  0.786  0.907  1.0
  Cs  Cs1  1  0.239  0.661  0.534  1.0
  Cs  Cs2  1  0.244  0.214  0.093  1.0
  Cs  Cs3  1  0.739  0.339  0.466  1.0
  Hg  Hg4  1  0.740  0.907  0.273  1.0
  Hg  Hg5  1  0.240  0.093  0.727  1.0
  I  I6  1  0.506  0.250  0.790  1.0
  I  I7  1  0.744  0.279  0.146  1.0
  I  I8  1  0.249  0.187  0.456  1.0
  I  I9  1  0.977  0.259  0.783  1.0
  I  I10  1  0.244  0.721  0.854  1.0
  I  I11  1  0.006  0.750  0.210  1.0
  I  I12  1  0.749  0.813  0.544  1.0
  I  I13  1  0.477  0.741  0.217  1.0
[/CIF]
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The material structure described by Cs2HgI4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one I(3), two equivalent I(1), two equivalent I(4), and three equivalent I(2) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one I(2), two equivalent I(1), two equivalent I(4), and three equivalent I(3) atoms. Hg(1) is bonded in a tetrahedral geometry to one I(1), one I(2), one I(3), and one I(4) atom. There are four inequivalent I sites. In the first I site, I(1) is bonded in a 5-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and one Hg(1) atom. In the second I site, I(2) is bonded in a 5-coordinate geometry to one Cs(2), three equivalent Cs(1), and one Hg(1) atom. In the third I site, I(3) is bonded in a 5-coordinate geometry to one Cs(1), three equivalent Cs(2), and one Hg(1) atom. In the fourth I site, I(4) is bonded to two equivalent Cs(1), two equivalent Cs(2), and one Hg(1) atom to form distorted corner-sharing ICs4Hg square pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cs2HgI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.657
_cell_length_b   8.121
_cell_length_c   11.394
_cell_angle_alpha   68.468
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   745.157
_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  0.744  0.786  0.907  1.0
  Cs  Cs1  1  0.239  0.661  0.534  1.0
  Cs  Cs2  1  0.244  0.214  0.093  1.0
  Cs  Cs3  1  0.739  0.339  0.466  1.0
  Hg  Hg4  1  0.740  0.907  0.273  1.0
  Hg  Hg5  1  0.240  0.093  0.727  1.0
  I  I6  1  0.506  0.250  0.790  1.0
  I  I7  1  0.744  0.279  0.146  1.0
  I  I8  1  0.249  0.187  0.456  1.0
  I  I9  1  0.977  0.259  0.783  1.0
  I  I10  1  0.244  0.721  0.854  1.0
  I  I11  1  0.006  0.750  0.210  1.0
  I  I12  1  0.749  0.813  0.544  1.0
  I  I13  1  0.477  0.741  0.217  1.0
[/CIF]
.