data_BeSn2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.21
_cell_length_b   5.21
_cell_length_c   5.21
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeSn2Bi
_chemical_formula_sum   'Be1 Sn2 Bi1'
_cell_volume   100.21
_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
  Be  Be0  1  0.0  0.0  0.0  1.0
  Sn  Sn2  1  0.69  0.69  0.69  1.0
  Sn  Sn3  1  0.84  0.84  0.84  1.0
  Bi  Bi1  1  0.53  0.53  0.53  1.0

data_BeSn2Bi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.21
_cell_length_b   5.21
_cell_length_c   12.77
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   BeSn2Bi
_chemical_formula_sum   'Be3 Sn6 Bi3'
_cell_volume   300.64
_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
  Be  Be0  3  0.0  0.0  0.0  1.0
  Sn  Sn1  3  0.0  0.0  0.16  1.0
  Sn  Sn2  3  0.0  0.0  0.31  1.0
  Bi  Bi3  3  0.0  0.0  0.47  1.0

Be Sn Sn Bi
Be Sn Sn Bi 0 2 - - - 1 3 o o o 1 2 o o o 
BeSn2Bi crystallizes in the trigonal R3m space group. Be(1) is bonded in a single-bond geometry to one Sn(2) and three equivalent Sn(1) atoms. The Be(1)-Sn(2) bond length is 2.00 Å. All Be(1)-Sn(1) bond lengths are 3.02 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to three equivalent Be(1), one Sn(2), and one Bi(1) atom to form distorted corner-sharing SnBe3SnBi trigonal bipyramids. The Sn(1)-Sn(2) bond length is 2.00 Å. The Sn(1)-Bi(1) bond length is 2.00 Å. In the second Sn site, Sn(2) is bonded in a 5-coordinate geometry to one Be(1), one Sn(1), and three equivalent Bi(1) atoms. All Sn(2)-Bi(1) bond lengths are 3.02 Å. Bi(1) is bonded in a distorted single-bond geometry to one Sn(1) and three equivalent Sn(2) atoms.