The structure described by Hg4CdSe5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to three equivalent Se(1) and three equivalent Se(3) atoms to form HgSe6 octahedra that share corners with three equivalent Hg(2)Se6 octahedra, corners with three equivalent Cd(1)Se6 octahedra, edges with three equivalent Hg(2)Se6 octahedra, edges with three equivalent Cd(1)Se6 octahedra, and edges with six equivalent Hg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Hg site, Hg(2) is bonded to three equivalent Se(2) and three equivalent Se(3) atoms to form a mixture of corner and edge-sharing HgSe6 octahedra. The corner-sharing octahedra are not tilted. Cd(1) is bonded to six equivalent Se(1) atoms to form CdSe6 octahedra that share corners with six equivalent Hg(1)Se6 octahedra, edges with six equivalent Hg(1)Se6 octahedra, and edges with six equivalent Cd(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Hg(1) and three equivalent Cd(1) atoms to form SeCd3Hg3 octahedra that share corners with three equivalent Se(1)Cd3Hg3 octahedra, corners with three equivalent Se(3)Hg6 octahedra, edges with three equivalent Se(3)Hg6 octahedra, and edges with nine equivalent Se(1)Cd3Hg3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to six equivalent Hg(2) atoms to form a mixture of corner and edge-sharing SeHg6 octahedra. The corner-sharing octahedra are not tilted. In the third Se site, Se(3) is bonded to three equivalent Hg(1) and three equivalent Hg(2) atoms to form SeHg6 octahedra that share corners with three equivalent Se(1)Cd3Hg3 octahedra, corners with three equivalent Se(2)Hg6 octahedra, edges with three equivalent Se(1)Cd3Hg3 octahedra, edges with three equivalent Se(2)Hg6 octahedra, and edges with six equivalent Se(3)Hg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. is represented by the CIF file [CIF]
data_CdHg4Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   16.927
_cell_length_b   16.927
_cell_length_c   16.927
_cell_angle_alpha   13.940
_cell_angle_beta   13.940
_cell_angle_gamma   13.940
_symmetry_Int_Tables_number   1
_cell_volume   244.985
_cell_formula_units_Z   1
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
  Cd  Cd0  1  0.000  0.000  0.000  1.0
  Hg  Hg1  1  0.600  0.600  0.600  1.0
  Hg  Hg2  1  0.200  0.200  0.200  1.0
  Hg  Hg3  1  0.800  0.800  0.800  1.0
  Hg  Hg4  1  0.400  0.400  0.400  1.0
  Se  Se5  1  0.699  0.699  0.699  1.0
  Se  Se6  1  0.500  0.500  0.500  1.0
  Se  Se7  1  0.100  0.100  0.100  1.0
  Se  Se8  1  0.301  0.301  0.301  1.0
  Se  Se9  1  0.900  0.900  0.900  1.0
[/CIF]
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The structure described by Hg4CdSe5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to three equivalent Se(1) and three equivalent Se(3) atoms to form HgSe6 octahedra that share corners with three equivalent Hg(2)Se6 octahedra, corners with three equivalent Cd(1)Se6 octahedra, edges with three equivalent Hg(2)Se6 octahedra, edges with three equivalent Cd(1)Se6 octahedra, and edges with six equivalent Hg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Hg site, Hg(2) is bonded to three equivalent Se(2) and three equivalent Se(3) atoms to form a mixture of corner and edge-sharing HgSe6 octahedra. The corner-sharing octahedra are not tilted. Cd(1) is bonded to six equivalent Se(1) atoms to form CdSe6 octahedra that share corners with six equivalent Hg(1)Se6 octahedra, edges with six equivalent Hg(1)Se6 octahedra, and edges with six equivalent Cd(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Hg(1) and three equivalent Cd(1) atoms to form SeCd3Hg3 octahedra that share corners with three equivalent Se(1)Cd3Hg3 octahedra, corners with three equivalent Se(3)Hg6 octahedra, edges with three equivalent Se(3)Hg6 octahedra, and edges with nine equivalent Se(1)Cd3Hg3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to six equivalent Hg(2) atoms to form a mixture of corner and edge-sharing SeHg6 octahedra. The corner-sharing octahedra are not tilted. In the third Se site, Se(3) is bonded to three equivalent Hg(1) and three equivalent Hg(2) atoms to form SeHg6 octahedra that share corners with three equivalent Se(1)Cd3Hg3 octahedra, corners with three equivalent Se(2)Hg6 octahedra, edges with three equivalent Se(1)Cd3Hg3 octahedra, edges with three equivalent Se(2)Hg6 octahedra, and edges with six equivalent Se(3)Hg6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. is represented by the CIF file [CIF]
data_CdHg4Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   16.927
_cell_length_b   16.927
_cell_length_c   16.927
_cell_angle_alpha   13.940
_cell_angle_beta   13.940
_cell_angle_gamma   13.940
_symmetry_Int_Tables_number   1
_cell_volume   244.985
_cell_formula_units_Z   1
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
  Cd  Cd0  1  0.000  0.000  0.000  1.0
  Hg  Hg1  1  0.600  0.600  0.600  1.0
  Hg  Hg2  1  0.200  0.200  0.200  1.0
  Hg  Hg3  1  0.800  0.800  0.800  1.0
  Hg  Hg4  1  0.400  0.400  0.400  1.0
  Se  Se5  1  0.699  0.699  0.699  1.0
  Se  Se6  1  0.500  0.500  0.500  1.0
  Se  Se7  1  0.100  0.100  0.100  1.0
  Se  Se8  1  0.301  0.301  0.301  1.0
  Se  Se9  1  0.900  0.900  0.900  1.0
[/CIF]
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