The material described by HgCr2S4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form edge-sharing CrS6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form edge-sharing CrS6 octahedra. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a 6-coordinate geometry to two equivalent S(2) and four equivalent S(1) atoms. In the second Hg site, Hg(2) is bonded in a 6-coordinate geometry to two equivalent S(3) and four equivalent S(1) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Cr(2), two equivalent Cr(1), one Hg(1), and one Hg(2) atom to form distorted SCr3Hg2 trigonal bipyramids that share corners with five equivalent S(1)Cr3Hg2 trigonal bipyramids, corners with two equivalent S(3)Cr3Hg trigonal pyramids, edges with four equivalent S(1)Cr3Hg2 trigonal bipyramids, and edges with two equivalent S(3)Cr3Hg trigonal pyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(2), and one Hg(1) atom. In the third S site, S(3) is bonded to one Cr(1), two equivalent Cr(2), and one Hg(2) atom to form SCr3Hg trigonal pyramids that share corners with four equivalent S(1)Cr3Hg2 trigonal bipyramids, corners with three equivalent S(3)Cr3Hg trigonal pyramids, and edges with four equivalent S(1)Cr3Hg2 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr2HgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.080
_cell_length_b   6.972
_cell_length_c   13.422
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   568.942
_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  0.999  0.000  0.244  1.0
  Cr  Cr1  1  0.999  0.000  0.756  1.0
  Cr  Cr2  1  0.001  0.500  0.256  1.0
  Cr  Cr3  1  0.001  0.500  0.744  1.0
  Cr  Cr4  1  0.500  0.250  0.250  1.0
  Cr  Cr5  1  0.500  0.750  0.750  1.0
  Cr  Cr6  1  0.500  0.750  0.250  1.0
  Cr  Cr7  1  0.500  0.250  0.750  1.0
  Hg  Hg8  1  0.378  0.000  0.000  1.0
  Hg  Hg9  1  0.622  0.500  0.500  1.0
  Hg  Hg10  1  0.050  0.000  0.500  1.0
  Hg  Hg11  1  0.950  0.500  0.000  1.0
  S  S12  1  0.832  0.252  0.350  1.0
  S  S13  1  0.832  0.748  0.650  1.0
  S  S14  1  0.168  0.752  0.150  1.0
  S  S15  1  0.168  0.248  0.850  1.0
  S  S16  1  0.168  0.248  0.150  1.0
  S  S17  1  0.168  0.752  0.850  1.0
  S  S18  1  0.832  0.748  0.350  1.0
  S  S19  1  0.832  0.252  0.650  1.0
  S  S20  1  0.656  0.000  0.154  1.0
  S  S21  1  0.656  0.000  0.846  1.0
  S  S22  1  0.344  0.500  0.346  1.0
  S  S23  1  0.344  0.500  0.654  1.0
  S  S24  1  0.327  0.000  0.344  1.0
  S  S25  1  0.327  0.000  0.656  1.0
  S  S26  1  0.673  0.500  0.156  1.0
  S  S27  1  0.673  0.500  0.844  1.0
[/CIF]
.
The material described by HgCr2S4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form edge-sharing CrS6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form edge-sharing CrS6 octahedra. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a 6-coordinate geometry to two equivalent S(2) and four equivalent S(1) atoms. In the second Hg site, Hg(2) is bonded in a 6-coordinate geometry to two equivalent S(3) and four equivalent S(1) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Cr(2), two equivalent Cr(1), one Hg(1), and one Hg(2) atom to form distorted SCr3Hg2 trigonal bipyramids that share corners with five equivalent S(1)Cr3Hg2 trigonal bipyramids, corners with two equivalent S(3)Cr3Hg trigonal pyramids, edges with four equivalent S(1)Cr3Hg2 trigonal bipyramids, and edges with two equivalent S(3)Cr3Hg trigonal pyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(2), and one Hg(1) atom. In the third S site, S(3) is bonded to one Cr(1), two equivalent Cr(2), and one Hg(2) atom to form SCr3Hg trigonal pyramids that share corners with four equivalent S(1)Cr3Hg2 trigonal bipyramids, corners with three equivalent S(3)Cr3Hg trigonal pyramids, and edges with four equivalent S(1)Cr3Hg2 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr2HgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.080
_cell_length_b   6.972
_cell_length_c   13.422
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   568.942
_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  0.999  0.000  0.244  1.0
  Cr  Cr1  1  0.999  0.000  0.756  1.0
  Cr  Cr2  1  0.001  0.500  0.256  1.0
  Cr  Cr3  1  0.001  0.500  0.744  1.0
  Cr  Cr4  1  0.500  0.250  0.250  1.0
  Cr  Cr5  1  0.500  0.750  0.750  1.0
  Cr  Cr6  1  0.500  0.750  0.250  1.0
  Cr  Cr7  1  0.500  0.250  0.750  1.0
  Hg  Hg8  1  0.378  0.000  0.000  1.0
  Hg  Hg9  1  0.622  0.500  0.500  1.0
  Hg  Hg10  1  0.050  0.000  0.500  1.0
  Hg  Hg11  1  0.950  0.500  0.000  1.0
  S  S12  1  0.832  0.252  0.350  1.0
  S  S13  1  0.832  0.748  0.650  1.0
  S  S14  1  0.168  0.752  0.150  1.0
  S  S15  1  0.168  0.248  0.850  1.0
  S  S16  1  0.168  0.248  0.150  1.0
  S  S17  1  0.168  0.752  0.850  1.0
  S  S18  1  0.832  0.748  0.350  1.0
  S  S19  1  0.832  0.252  0.650  1.0
  S  S20  1  0.656  0.000  0.154  1.0
  S  S21  1  0.656  0.000  0.846  1.0
  S  S22  1  0.344  0.500  0.346  1.0
  S  S23  1  0.344  0.500  0.654  1.0
  S  S24  1  0.327  0.000  0.344  1.0
  S  S25  1  0.327  0.000  0.656  1.0
  S  S26  1  0.673  0.500  0.156  1.0
  S  S27  1  0.673  0.500  0.844  1.0
[/CIF]
.