The compound described by HgGa2Se4 crystallizes in the tetragonal I-4m2 space group. Hg(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form HgSe6 octahedra that share corners with two equivalent Ga(1)Se6 octahedra, corners with four equivalent Hg(1)Se6 octahedra, edges with four equivalent Ga(1)Se6 octahedra, and edges with four equivalent Ga(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form GaSe6 octahedra that share corners with two equivalent Hg(1)Se6 octahedra, corners with four equivalent Ga(1)Se6 octahedra, edges with four equivalent Hg(1)Se6 octahedra, and edges with four equivalent Ga(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second Ga site, Ga(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form GaSe6 octahedra that share corners with four equivalent Ga(2)Se6 octahedra, edges with four equivalent Hg(1)Se6 octahedra, and edges with four equivalent Ga(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Hg(1), one Ga(2), and two equivalent Ga(1) atoms to form a mixture of corner and edge-sharing SeGa3Hg2 square pyramids. In the second Se site, Se(2) is bonded in a square co-planar geometry to one Hg(1), one Ga(1), and two equivalent Ga(2) atoms. is represented by the CIF card [CIF]
data_Ga2HgSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.722
_cell_length_b   6.722
_cell_length_c   6.722
_cell_angle_alpha   130.884
_cell_angle_beta   130.884
_cell_angle_gamma   71.998
_symmetry_Int_Tables_number   1
_cell_volume   169.806
_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
  Ga  Ga0  1  0.500  0.500  0.000  1.0
  Ga  Ga1  1  0.250  0.750  0.500  1.0
  Hg  Hg2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.477  0.977  0.500  1.0
  Se  Se4  1  0.275  0.275  0.000  1.0
  Se  Se5  1  0.023  0.523  0.500  1.0
  Se  Se6  1  0.725  0.725  0.000  1.0
[/CIF]
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The compound described by HgGa2Se4 crystallizes in the tetragonal I-4m2 space group. Hg(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form HgSe6 octahedra that share corners with two equivalent Ga(1)Se6 octahedra, corners with four equivalent Hg(1)Se6 octahedra, edges with four equivalent Ga(1)Se6 octahedra, and edges with four equivalent Ga(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form GaSe6 octahedra that share corners with two equivalent Hg(1)Se6 octahedra, corners with four equivalent Ga(1)Se6 octahedra, edges with four equivalent Hg(1)Se6 octahedra, and edges with four equivalent Ga(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second Ga site, Ga(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form GaSe6 octahedra that share corners with four equivalent Ga(2)Se6 octahedra, edges with four equivalent Hg(1)Se6 octahedra, and edges with four equivalent Ga(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Hg(1), one Ga(2), and two equivalent Ga(1) atoms to form a mixture of corner and edge-sharing SeGa3Hg2 square pyramids. In the second Se site, Se(2) is bonded in a square co-planar geometry to one Hg(1), one Ga(1), and two equivalent Ga(2) atoms. is represented by the CIF card [CIF]
data_Ga2HgSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.722
_cell_length_b   6.722
_cell_length_c   6.722
_cell_angle_alpha   130.884
_cell_angle_beta   130.884
_cell_angle_gamma   71.998
_symmetry_Int_Tables_number   1
_cell_volume   169.806
_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
  Ga  Ga0  1  0.500  0.500  0.000  1.0
  Ga  Ga1  1  0.250  0.750  0.500  1.0
  Hg  Hg2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.477  0.977  0.500  1.0
  Se  Se4  1  0.275  0.275  0.000  1.0
  Se  Se5  1  0.023  0.523  0.500  1.0
  Se  Se6  1  0.725  0.725  0.000  1.0
[/CIF]
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