data_CaAgHgSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   5.15
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaAgHgSe
_chemical_formula_sum   'Ca1 Ag1 Hg1 Se1'
_cell_volume   96.66
_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
  Ca  Ca1  1  0.0  0.0  0.0  1.0
  Ag  Ag0  1  0.82  0.82  0.82  1.0
  Hg  Hg2  1  0.64  0.64  0.64  1.0
  Se  Se3  1  0.46  0.46  0.46  1.0

data_CaAgHgSe
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   12.62
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaAgHgSe
_chemical_formula_sum   'Ca3 Ag3 Hg3 Se3'
_cell_volume   289.98
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Ca  Ca0  3  0.0  0.0  0.0  1.0
  Ag  Ag1  3  0.0  0.0  0.18  1.0
  Hg  Hg2  3  0.0  0.0  0.36  1.0
  Se  Se3  3  0.0  0.0  0.54  1.0

Ca Ag Hg Se
CaAgHgSe crystallizes in the trigonal R3m space group. Ca(1) is bonded in a 1-coordinate geometry to one Ag(1), three equivalent Hg(1), and three equivalent Se(1) atoms. The Ca(1)-Ag(1) bond length is 2.26 Å. All Ca(1)-Hg(1) bond lengths are 2.99 Å. All Ca(1)-Se(1) bond lengths are 3.40 Å. Ag(1) is bonded in a 5-coordinate geometry to one Ca(1), one Hg(1), and three equivalent Se(1) atoms. The Ag(1)-Hg(1) bond length is 2.26 Å. All Ag(1)-Se(1) bond lengths are 2.99 Å. Hg(1) is bonded to three equivalent Ca(1), one Ag(1), and one Se(1) atom to form corner-sharing HgCa3AgSe trigonal bipyramids. The Hg(1)-Se(1) bond length is 2.26 Å. Se(1) is bonded in a 7-coordinate geometry to three equivalent Ca(1), three equivalent Ag(1), and one Hg(1) atom.