data_Fe4SnHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.03
_cell_length_b   5.03
_cell_length_c   5.03
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe4SnHg
_chemical_formula_sum   'Fe4 Sn1 Hg1'
_cell_volume   89.89
_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
  Fe  Fe0  1  0.45  0.45  0.67  1.0
  Fe  Fe1  1  0.45  0.67  0.45  1.0
  Fe  Fe2  1  0.67  0.45  0.45  1.0
  Fe  Fe3  1  0.67  0.67  0.67  1.0
  Sn  Sn5  1  0.0  0.0  0.0  1.0
  Hg  Hg4  1  0.33  0.33  0.33  1.0

data_Fe4SnHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.03
_cell_length_b   5.03
_cell_length_c   12.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Fe4SnHg
_chemical_formula_sum   'Fe12 Sn3 Hg3'
_cell_volume   269.67
_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
  Fe  Fe0  9  0.07  0.15  0.48  1.0
  Fe  Fe1  3  0.0  0.0  0.33  1.0
  Sn  Sn2  3  0.0  0.0  0.0  1.0
  Hg  Hg3  3  0.0  0.0  0.67  1.0

Fe Fe Fe Fe Sn Hg
Fe4HgSn crystallizes in the trigonal R3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one Fe(2), two equivalent Fe(1), two equivalent Hg(1), and three equivalent Sn(1) atoms. The Fe(1)-Fe(2) bond length is 1.92 Å. Both Fe(1)-Fe(1) bond lengths are 1.11 Å. There is one shorter (2.37 Å) and one longer (2.90 Å) Fe(1)-Hg(1) bond length. All Fe(1)-Sn(1) bond lengths are 3.21 Å. In the second Fe site, Fe(2) is bonded in a 9-coordinate geometry to three equivalent Fe(1), three equivalent Hg(1), and three equivalent Sn(1) atoms. All Fe(2)-Hg(1) bond lengths are 2.90 Å. All Fe(2)-Sn(1) bond lengths are 2.90 Å. Hg(1) is bonded to three equivalent Fe(2), six equivalent Fe(1), and three equivalent Sn(1) atoms to form a mixture of edge and corner-sharing HgFe9Sn3 cuboctahedra. All Hg(1)-Sn(1) bond lengths are 2.90 Å. Sn(1) is bonded in a 15-coordinate geometry to three equivalent Fe(2), nine equivalent Fe(1), and three equivalent Hg(1) atoms.