data_Na2CdHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   5.19
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2CdHg
_chemical_formula_sum   'Na2 Cd1 Hg1'
_cell_volume   99.13
_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
  Na  Na2  1  0.0  0.0  0.0  1.0
  Na  Na3  1  0.51  0.51  0.51  1.0
  Cd  Cd0  1  0.67  0.67  0.67  1.0
  Hg  Hg1  1  0.84  0.84  0.84  1.0

data_Na2CdHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   12.72
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na2CdHg
_chemical_formula_sum   'Na6 Cd3 Hg3'
_cell_volume   297.39
_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
  Na  Na0  3  0.0  0.0  0.0  1.0
  Na  Na1  3  0.0  0.0  0.49  1.0
  Cd  Cd2  3  0.0  0.0  0.33  1.0
  Hg  Hg3  3  0.0  0.0  0.16  1.0

Na Na Cd Hg
Na2HgCd crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted single-bond geometry to one Hg(1) and three equivalent Cd(1) atoms. The Na(1)-Hg(1) bond length is 2.08 Å. All Na(1)-Cd(1) bond lengths are 3.00 Å. In the second Na site, Na(2) is bonded to three equivalent Hg(1) and one Cd(1) atom to form distorted NaCdHg3 trigonal pyramids that share  a cornercorner with one Hg(1)Na4Cd trigonal bipyramid, corners with three equivalent Cd(1)Na4Hg trigonal bipyramids, and corners with six equivalent Na(2)CdHg3 trigonal pyramids. All Na(2)-Hg(1) bond lengths are 3.00 Å. The Na(2)-Cd(1) bond length is 2.08 Å. Hg(1) is bonded to one Na(1), three equivalent Na(2), and one Cd(1) atom to form distorted HgNa4Cd trigonal bipyramids that share corners with six equivalent Hg(1)Na4Cd trigonal bipyramids,  a cornercorner with one Na(2)CdHg3 trigonal pyramid, and edges with three equivalent Cd(1)Na4Hg trigonal bipyramids. The Hg(1)-Cd(1) bond length is 2.08 Å. Cd(1) is bonded to one Na(2), three equivalent Na(1), and one Hg(1) atom to form distorted CdNa4Hg trigonal bipyramids that share corners with six equivalent Cd(1)Na4Hg trigonal bipyramids, corners with three equivalent Na(2)CdHg3 trigonal pyramids, and edges with three equivalent Hg(1)Na4Cd trigonal bipyramids.