data_Mg2SnHg
_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   Mg2SnHg
_chemical_formula_sum   'Mg2 Sn1 Hg1'
_cell_volume   96.34
_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
  Mg  Mg1  1  0.46  0.46  0.46  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.64  0.64  0.64  1.0
  Hg  Hg0  1  0.82  0.82  0.82  1.0

data_Mg2SnHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   12.6
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Mg2SnHg
_chemical_formula_sum   'Mg6 Sn3 Hg3'
_cell_volume   289.03
_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
  Mg  Mg0  3  0.0  0.0  0.0  1.0
  Mg  Mg1  3  0.0  0.0  0.54  1.0
  Sn  Sn2  3  0.0  0.0  0.36  1.0
  Hg  Hg3  3  0.0  0.0  0.18  1.0

Mg Mg Sn Hg
Mg2HgSn crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to three equivalent Hg(1) and one Sn(1) atom. All Mg(1)-Hg(1) bond lengths are 2.99 Å. The Mg(1)-Sn(1) bond length is 2.28 Å. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to one Hg(1) and three equivalent Sn(1) atoms. The Mg(2)-Hg(1) bond length is 2.28 Å. All Mg(2)-Sn(1) bond lengths are 2.99 Å. Hg(1) is bonded to one Mg(2), three equivalent Mg(1), and one Sn(1) atom to form distorted HgMg4Sn trigonal bipyramids that share corners with six equivalent Hg(1)Mg4Sn trigonal bipyramids and edges with three equivalent Sn(1)Mg4Hg trigonal bipyramids. The Hg(1)-Sn(1) bond length is 2.28 Å. Sn(1) is bonded to one Mg(1), three equivalent Mg(2), and one Hg(1) atom to form distorted SnMg4Hg trigonal bipyramids that share corners with six equivalent Sn(1)Mg4Hg trigonal bipyramids and edges with three equivalent Hg(1)Mg4Sn trigonal bipyramids.