data_CaHgGeSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.12
_cell_length_b   5.12
_cell_length_c   5.12
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaHgGeSe
_chemical_formula_sum   'Ca1 Hg1 Ge1 Se1'
_cell_volume   95.1
_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  Ca0  1  0.0  0.0  0.0  1.0
  Hg  Hg2  1  0.62  0.62  0.62  1.0
  Ge  Ge1  1  0.43  0.43  0.43  1.0
  Se  Se3  1  0.81  0.81  0.81  1.0

data_CaHgGeSe
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.12
_cell_length_b   5.12
_cell_length_c   12.55
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaHgGeSe
_chemical_formula_sum   'Ca3 Hg3 Ge3 Se3'
_cell_volume   285.31
_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
  Hg  Hg1  3  0.0  0.0  0.38  1.0
  Ge  Ge2  3  0.0  0.0  0.57  1.0
  Se  Se3  3  0.0  0.0  0.19  1.0

Ca Hg Ge Se
CaHgGeSe crystallizes in the trigonal R3m space group. Ca(1) is bonded in a distorted single-bond geometry to three equivalent Hg(1), three equivalent Ge(1), and one Se(1) atom. All Ca(1)-Hg(1) bond lengths are 3.01 Å. All Ca(1)-Ge(1) bond lengths are 3.22 Å. The Ca(1)-Se(1) bond length is 2.37 Å. Hg(1) is bonded to three equivalent Ca(1), one Ge(1), and one Se(1) atom to form distorted HgCa3GeSe trigonal bipyramids that share corners with three equivalent Ge(1)Ca3HgSe3 hexagonal pyramids, corners with six equivalent Hg(1)Ca3GeSe trigonal bipyramids, and faces with three equivalent Ge(1)Ca3HgSe3 hexagonal pyramids. The Hg(1)-Ge(1) bond length is 2.37 Å. The Hg(1)-Se(1) bond length is 2.37 Å. Ge(1) is bonded to three equivalent Ca(1), one Hg(1), and three equivalent Se(1) atoms to form distorted GeCa3HgSe3 hexagonal pyramids that share corners with three equivalent Hg(1)Ca3GeSe trigonal bipyramids, edges with six equivalent Ge(1)Ca3HgSe3 hexagonal pyramids, and faces with three equivalent Hg(1)Ca3GeSe trigonal bipyramids. All Ge(1)-Se(1) bond lengths are 3.01 Å. Se(1) is bonded in a distorted linear geometry to one Ca(1), one Hg(1), and three equivalent Ge(1) atoms.