data_Ca2SnHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.48
_cell_length_b   5.48
_cell_length_c   5.48
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2SnHg
_chemical_formula_sum   'Ca2 Sn1 Hg1'
_cell_volume   116.58
_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  0.94  0.94  0.94  1.0
  Ca  Ca1  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.88  0.88  0.88  1.0
  Hg  Hg2  1  0.82  0.82  0.82  1.0

data_Ca2SnHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.48
_cell_length_b   5.48
_cell_length_c   13.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ca2SnHg
_chemical_formula_sum   'Ca6 Sn3 Hg3'
_cell_volume   349.75
_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
  Ca  Ca1  3  0.0  0.0  0.06  1.0
  Sn  Sn2  3  0.0  0.0  0.12  1.0
  Hg  Hg3  3  0.0  0.0  0.18  1.0

Ca Ca Sn Hg
Ca Ca Sn Hg 0 2 o o o 0 1 + + + 2 3 o o o 
Ca2HgSn crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted linear geometry to one Ca(2) and one Sn(1) atom. The Ca(1)-Ca(2) bond length is 0.82 Å. The Ca(1)-Sn(1) bond length is 0.82 Å. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to one Ca(1) and three equivalent Hg(1) atoms. All Ca(2)-Hg(1) bond lengths are 3.75 Å. Hg(1) is bonded in a distorted single-bond geometry to three equivalent Ca(2) and one Sn(1) atom. The Hg(1)-Sn(1) bond length is 0.82 Å. Sn(1) is bonded in a linear geometry to one Ca(1) and one Hg(1) atom.