The compound described by K2HgCl4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent Cl(1), two equivalent Cl(2), and two equivalent Cl(3) atoms to form a mixture of edge, face, and corner-sharing KCl6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. In the second K site, K(2) is bonded to two equivalent Cl(1), two equivalent Cl(2), and two equivalent Cl(3) atoms to form a mixture of distorted edge, face, and corner-sharing KCl6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. Hg(1) is bonded in a distorted T-shaped geometry to one Cl(3) and two equivalent Cl(1) atoms. There are three inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a 3-coordinate geometry to one K(1), one K(2), and one Hg(1) atom. In the second Cl site, Cl(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1) and two equivalent K(2) atoms. In the third Cl site, Cl(3) is bonded to two equivalent K(1), two equivalent K(2), and one Hg(1) atom to form distorted corner-sharing ClK4Hg trigonal bipyramids. is represented by the CIF file [CIF]
data_K2HgCl4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.119
_cell_length_b   9.192
_cell_length_c   13.649
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1018.598
_cell_formula_units_Z   4
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
  K  K0  1  0.000  0.500  0.500  1.0
  K  K1  1  0.000  0.000  0.000  1.0
  K  K2  1  0.500  0.500  0.000  1.0
  K  K3  1  0.000  0.500  0.000  1.0
  K  K4  1  0.500  0.000  0.500  1.0
  K  K5  1  0.000  0.000  0.500  1.0
  K  K6  1  0.500  0.500  0.500  1.0
  K  K7  1  0.500  0.000  0.000  1.0
  Hg  Hg8  1  0.275  0.250  0.767  1.0
  Hg  Hg9  1  0.725  0.750  0.233  1.0
  Hg  Hg10  1  0.775  0.750  0.733  1.0
  Hg  Hg11  1  0.225  0.250  0.267  1.0
  Cl  Cl12  1  0.774  0.499  0.696  1.0
  Cl  Cl13  1  0.749  0.250  0.954  1.0
  Cl  Cl14  1  0.726  0.001  0.196  1.0
  Cl  Cl15  1  0.755  0.750  0.932  1.0
  Cl  Cl16  1  0.251  0.750  0.046  1.0
  Cl  Cl17  1  0.226  0.501  0.304  1.0
  Cl  Cl18  1  0.274  0.501  0.804  1.0
  Cl  Cl19  1  0.245  0.250  0.068  1.0
  Cl  Cl20  1  0.774  0.001  0.696  1.0
  Cl  Cl21  1  0.226  0.999  0.304  1.0
  Cl  Cl22  1  0.745  0.750  0.432  1.0
  Cl  Cl23  1  0.751  0.250  0.454  1.0
  Cl  Cl24  1  0.274  0.999  0.804  1.0
  Cl  Cl25  1  0.249  0.750  0.546  1.0
  Cl  Cl26  1  0.726  0.499  0.196  1.0
  Cl  Cl27  1  0.255  0.250  0.568  1.0
[/CIF]
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The compound described by K2HgCl4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent Cl(1), two equivalent Cl(2), and two equivalent Cl(3) atoms to form a mixture of edge, face, and corner-sharing KCl6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. In the second K site, K(2) is bonded to two equivalent Cl(1), two equivalent Cl(2), and two equivalent Cl(3) atoms to form a mixture of distorted edge, face, and corner-sharing KCl6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. Hg(1) is bonded in a distorted T-shaped geometry to one Cl(3) and two equivalent Cl(1) atoms. There are three inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a 3-coordinate geometry to one K(1), one K(2), and one Hg(1) atom. In the second Cl site, Cl(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1) and two equivalent K(2) atoms. In the third Cl site, Cl(3) is bonded to two equivalent K(1), two equivalent K(2), and one Hg(1) atom to form distorted corner-sharing ClK4Hg trigonal bipyramids. is represented by the CIF file [CIF]
data_K2HgCl4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.119
_cell_length_b   9.192
_cell_length_c   13.649
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1018.598
_cell_formula_units_Z   4
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
  K  K0  1  0.000  0.500  0.500  1.0
  K  K1  1  0.000  0.000  0.000  1.0
  K  K2  1  0.500  0.500  0.000  1.0
  K  K3  1  0.000  0.500  0.000  1.0
  K  K4  1  0.500  0.000  0.500  1.0
  K  K5  1  0.000  0.000  0.500  1.0
  K  K6  1  0.500  0.500  0.500  1.0
  K  K7  1  0.500  0.000  0.000  1.0
  Hg  Hg8  1  0.275  0.250  0.767  1.0
  Hg  Hg9  1  0.725  0.750  0.233  1.0
  Hg  Hg10  1  0.775  0.750  0.733  1.0
  Hg  Hg11  1  0.225  0.250  0.267  1.0
  Cl  Cl12  1  0.774  0.499  0.696  1.0
  Cl  Cl13  1  0.749  0.250  0.954  1.0
  Cl  Cl14  1  0.726  0.001  0.196  1.0
  Cl  Cl15  1  0.755  0.750  0.932  1.0
  Cl  Cl16  1  0.251  0.750  0.046  1.0
  Cl  Cl17  1  0.226  0.501  0.304  1.0
  Cl  Cl18  1  0.274  0.501  0.804  1.0
  Cl  Cl19  1  0.245  0.250  0.068  1.0
  Cl  Cl20  1  0.774  0.001  0.696  1.0
  Cl  Cl21  1  0.226  0.999  0.304  1.0
  Cl  Cl22  1  0.745  0.750  0.432  1.0
  Cl  Cl23  1  0.751  0.250  0.454  1.0
  Cl  Cl24  1  0.274  0.999  0.804  1.0
  Cl  Cl25  1  0.249  0.750  0.546  1.0
  Cl  Cl26  1  0.726  0.499  0.196  1.0
  Cl  Cl27  1  0.255  0.250  0.568  1.0
[/CIF]
.