The material structure described by HgCr2S4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(2) atoms to form a mixture of edge and corner-sharing CrS6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. In the second Cr site, Cr(2) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form a mixture of edge and corner-sharing CrS6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. Hg(1) is bonded in a 3-coordinate geometry to one S(1) and two equivalent S(3) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cr(2) and one Hg(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Cr(2) and three equivalent Cr(1) atoms. In the third S site, S(3) is bonded to one Cr(1), two equivalent Cr(2), and two equivalent Hg(1) atoms to form distorted edge-sharing SCr3Hg2 trigonal bipyramids. In the fourth S site, S(4) is bonded in a distorted trigonal non-coplanar geometry to one Cr(2) and two equivalent Cr(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr2HgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.462
_cell_length_b   3.559
_cell_length_c   11.736
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   520.561
_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
  Cr  Cr0  1  0.090  0.250  0.084  1.0
  Cr  Cr1  1  0.910  0.750  0.916  1.0
  Cr  Cr2  1  0.410  0.750  0.584  1.0
  Cr  Cr3  1  0.590  0.250  0.416  1.0
  Cr  Cr4  1  0.174  0.250  0.708  1.0
  Cr  Cr5  1  0.826  0.750  0.292  1.0
  Cr  Cr6  1  0.326  0.750  0.208  1.0
  Cr  Cr7  1  0.674  0.250  0.792  1.0
  Hg  Hg8  1  0.133  0.750  0.420  1.0
  Hg  Hg9  1  0.867  0.250  0.580  1.0
  Hg  Hg10  1  0.367  0.250  0.920  1.0
  Hg  Hg11  1  0.633  0.750  0.080  1.0
  S  S12  1  0.073  0.750  0.624  1.0
  S  S13  1  0.927  0.250  0.376  1.0
  S  S14  1  0.427  0.250  0.124  1.0
  S  S15  1  0.573  0.750  0.876  1.0
  S  S16  1  0.039  0.250  0.880  1.0
  S  S17  1  0.961  0.750  0.120  1.0
  S  S18  1  0.461  0.750  0.380  1.0
  S  S19  1  0.539  0.250  0.620  1.0
  S  S20  1  0.194  0.250  0.263  1.0
  S  S21  1  0.806  0.750  0.738  1.0
  S  S22  1  0.306  0.750  0.762  1.0
  S  S23  1  0.694  0.250  0.237  1.0
  S  S24  1  0.211  0.750  0.047  1.0
  S  S25  1  0.789  0.250  0.953  1.0
  S  S26  1  0.289  0.250  0.547  1.0
  S  S27  1  0.711  0.750  0.453  1.0
[/CIF]
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The material structure described by HgCr2S4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(2) atoms to form a mixture of edge and corner-sharing CrS6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. In the second Cr site, Cr(2) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form a mixture of edge and corner-sharing CrS6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. Hg(1) is bonded in a 3-coordinate geometry to one S(1) and two equivalent S(3) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cr(2) and one Hg(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Cr(2) and three equivalent Cr(1) atoms. In the third S site, S(3) is bonded to one Cr(1), two equivalent Cr(2), and two equivalent Hg(1) atoms to form distorted edge-sharing SCr3Hg2 trigonal bipyramids. In the fourth S site, S(4) is bonded in a distorted trigonal non-coplanar geometry to one Cr(2) and two equivalent Cr(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr2HgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.462
_cell_length_b   3.559
_cell_length_c   11.736
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   520.561
_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
  Cr  Cr0  1  0.090  0.250  0.084  1.0
  Cr  Cr1  1  0.910  0.750  0.916  1.0
  Cr  Cr2  1  0.410  0.750  0.584  1.0
  Cr  Cr3  1  0.590  0.250  0.416  1.0
  Cr  Cr4  1  0.174  0.250  0.708  1.0
  Cr  Cr5  1  0.826  0.750  0.292  1.0
  Cr  Cr6  1  0.326  0.750  0.208  1.0
  Cr  Cr7  1  0.674  0.250  0.792  1.0
  Hg  Hg8  1  0.133  0.750  0.420  1.0
  Hg  Hg9  1  0.867  0.250  0.580  1.0
  Hg  Hg10  1  0.367  0.250  0.920  1.0
  Hg  Hg11  1  0.633  0.750  0.080  1.0
  S  S12  1  0.073  0.750  0.624  1.0
  S  S13  1  0.927  0.250  0.376  1.0
  S  S14  1  0.427  0.250  0.124  1.0
  S  S15  1  0.573  0.750  0.876  1.0
  S  S16  1  0.039  0.250  0.880  1.0
  S  S17  1  0.961  0.750  0.120  1.0
  S  S18  1  0.461  0.750  0.380  1.0
  S  S19  1  0.539  0.250  0.620  1.0
  S  S20  1  0.194  0.250  0.263  1.0
  S  S21  1  0.806  0.750  0.738  1.0
  S  S22  1  0.306  0.750  0.762  1.0
  S  S23  1  0.694  0.250  0.237  1.0
  S  S24  1  0.211  0.750  0.047  1.0
  S  S25  1  0.789  0.250  0.953  1.0
  S  S26  1  0.289  0.250  0.547  1.0
  S  S27  1  0.711  0.750  0.453  1.0
[/CIF]
.