The material described by Cu2HgSiSe4 is Stannite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. Cu(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Hg(1)Se4 tetrahedra, and corners with four equivalent Si(1)Se4 tetrahedra. Hg(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form HgSe4 tetrahedra that share corners with four equivalent Si(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. Si(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form SiSe4 tetrahedra that share corners with four equivalent Hg(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cu(1), one Hg(1), and one Si(1) atom to form corner-sharing SeCu2SiHg tetrahedra. In the second Se site, Se(2) is bonded to two equivalent Cu(1), one Hg(1), and one Si(1) atom to form corner-sharing SeCu2SiHg tetrahedra. In the third Se site, Se(3) is bonded to two equivalent Cu(1), one Hg(1), and one Si(1) atom to form corner-sharing SeCu2SiHg tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cu2SiHgSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.650
_cell_length_b   6.861
_cell_length_c   8.124
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   370.680
_cell_formula_units_Z   2
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
  Cu  Cu0  1  0.511  0.824  0.753  1.0
  Cu  Cu1  1  0.011  0.176  0.747  1.0
  Cu  Cu2  1  0.011  0.176  0.253  1.0
  Cu  Cu3  1  0.511  0.824  0.247  1.0
  Si  Si4  1  0.000  0.679  0.000  1.0
  Si  Si5  1  0.500  0.321  0.500  1.0
  Hg  Hg6  1  0.514  0.349  0.000  1.0
  Hg  Hg7  1  0.014  0.651  0.500  1.0
  Se  Se8  1  0.918  0.349  0.000  1.0
  Se  Se9  1  0.418  0.651  0.500  1.0
  Se  Se10  1  0.874  0.845  0.773  1.0
  Se  Se11  1  0.374  0.155  0.727  1.0
  Se  Se12  1  0.374  0.155  0.273  1.0
  Se  Se13  1  0.874  0.845  0.227  1.0
  Se  Se14  1  0.350  0.709  0.000  1.0
  Se  Se15  1  0.850  0.291  0.500  1.0
[/CIF]
.
The material described by Cu2HgSiSe4 is Stannite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. Cu(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Hg(1)Se4 tetrahedra, and corners with four equivalent Si(1)Se4 tetrahedra. Hg(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form HgSe4 tetrahedra that share corners with four equivalent Si(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. Si(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form SiSe4 tetrahedra that share corners with four equivalent Hg(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cu(1), one Hg(1), and one Si(1) atom to form corner-sharing SeCu2SiHg tetrahedra. In the second Se site, Se(2) is bonded to two equivalent Cu(1), one Hg(1), and one Si(1) atom to form corner-sharing SeCu2SiHg tetrahedra. In the third Se site, Se(3) is bonded to two equivalent Cu(1), one Hg(1), and one Si(1) atom to form corner-sharing SeCu2SiHg tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cu2SiHgSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.650
_cell_length_b   6.861
_cell_length_c   8.124
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   370.680
_cell_formula_units_Z   2
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
  Cu  Cu0  1  0.511  0.824  0.753  1.0
  Cu  Cu1  1  0.011  0.176  0.747  1.0
  Cu  Cu2  1  0.011  0.176  0.253  1.0
  Cu  Cu3  1  0.511  0.824  0.247  1.0
  Si  Si4  1  0.000  0.679  0.000  1.0
  Si  Si5  1  0.500  0.321  0.500  1.0
  Hg  Hg6  1  0.514  0.349  0.000  1.0
  Hg  Hg7  1  0.014  0.651  0.500  1.0
  Se  Se8  1  0.918  0.349  0.000  1.0
  Se  Se9  1  0.418  0.651  0.500  1.0
  Se  Se10  1  0.874  0.845  0.773  1.0
  Se  Se11  1  0.374  0.155  0.727  1.0
  Se  Se12  1  0.374  0.155  0.273  1.0
  Se  Se13  1  0.874  0.845  0.227  1.0
  Se  Se14  1  0.350  0.709  0.000  1.0
  Se  Se15  1  0.850  0.291  0.500  1.0
[/CIF]
.