data_FeSn2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeSn2Bi
_chemical_formula_sum   'Fe1 Sn2 Bi1'
_cell_volume   98.45
_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  Fe1  1  0.0  0.0  0.0  1.0
  Sn  Sn2  1  0.83  0.83  0.83  1.0
  Sn  Sn3  1  0.66  0.66  0.66  1.0
  Bi  Bi0  1  0.5  0.5  0.5  1.0

data_FeSn2Bi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   12.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   FeSn2Bi
_chemical_formula_sum   'Fe3 Sn6 Bi3'
_cell_volume   295.36
_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  3  0.0  0.0  0.0  1.0
  Sn  Sn1  3  0.0  0.0  0.17  1.0
  Sn  Sn2  3  0.0  0.0  0.34  1.0
  Bi  Bi3  3  0.0  0.0  0.5  1.0

Fe Sn Sn Bi
Fe Sn Sn Bi 0 1 - - - 1 2 o o o 2 3 o o o 
FeSn2Bi crystallizes in the trigonal R3m space group. Fe(1) is bonded to one Sn(1) and three equivalent Sn(2) atoms to form distorted FeSn4 trigonal pyramids that share  a cornercorner with one Sn(2)Fe3SnBi trigonal bipyramid, corners with three equivalent Sn(1)FeSnBi3 trigonal bipyramids, corners with six equivalent Fe(1)Sn4 trigonal pyramids, and edges with three equivalent Bi(1)Sn4 trigonal pyramids. The Fe(1)-Sn(1) bond length is 2.13 Å. All Fe(1)-Sn(2) bond lengths are 2.99 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Fe(1), one Sn(2), and three equivalent Bi(1) atoms to form distorted SnFeSnBi3 trigonal bipyramids that share corners with six equivalent Sn(1)FeSnBi3 trigonal bipyramids,  a cornercorner with one Bi(1)Sn4 trigonal pyramid, corners with three equivalent Fe(1)Sn4 trigonal pyramids, and edges with three equivalent Sn(2)Fe3SnBi trigonal bipyramids. The Sn(1)-Sn(2) bond length is 2.13 Å. All Sn(1)-Bi(1) bond lengths are 2.99 Å. In the second Sn site, Sn(2) is bonded to three equivalent Fe(1), one Sn(1), and one Bi(1) atom to form SnFe3SnBi trigonal bipyramids that share corners with six equivalent Sn(2)Fe3SnBi trigonal bipyramids,  a cornercorner with one Fe(1)Sn4 trigonal pyramid, corners with three equivalent Bi(1)Sn4 trigonal pyramids, and edges with three equivalent Sn(1)FeSnBi3 trigonal bipyramids. The Sn(2)-Bi(1) bond length is 2.13 Å. Bi(1) is bonded to one Sn(2) and three equivalent Sn(1) atoms to form distorted BiSn4 trigonal pyramids that share  a cornercorner with one Sn(1)FeSnBi3 trigonal bipyramid, corners with three equivalent Sn(2)Fe3SnBi trigonal bipyramids, corners with six equivalent Bi(1)Sn4 trigonal pyramids, and edges with three equivalent Fe(1)Sn4 trigonal pyramids.