data_SrBe4Tl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.25
_cell_length_b   5.25
_cell_length_c   5.25
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrBe4Tl
_chemical_formula_sum   'Sr1 Be4 Tl1'
_cell_volume   102.03
_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
  Sr  Sr4  1  0.0  0.0  0.0  1.0
  Be  Be0  1  0.66  0.66  0.76  1.0
  Be  Be1  1  0.66  0.76  0.66  1.0
  Be  Be2  1  0.76  0.66  0.66  1.0
  Be  Be3  1  0.76  0.76  0.76  1.0
  Tl  Tl5  1  0.85  0.85  0.85  1.0

data_SrBe4Tl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.25
_cell_length_b   5.25
_cell_length_c   12.85
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrBe4Tl
_chemical_formula_sum   'Sr3 Be12 Tl3'
_cell_volume   306.1
_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
  Sr  Sr0  3  0.0  0.0  0.0  1.0
  Be  Be1  9  0.03  0.06  0.31  1.0
  Be  Be2  3  0.0  0.0  0.24  1.0
  Tl  Tl3  3  0.0  0.0  0.15  1.0

Sr Be Be Be Be Tl
Sr Be Be Be Be Tl 0 5 - - - 1 3 o o o 1 2 o o o 1 4 o o o 2 3 o o o 2 4 o o o 3 4 o o o 4 5 o o o 
SrBe4Tl is Copper structured and crystallizes in the trigonal R3m space group. The structure is zero-dimensional and consists of three SrBe4Tl clusters. Sr(1) is bonded in a single-bond geometry to one Tl(1) atom. The Sr(1)-Tl(1) bond length is 1.87 Å. There are two inequivalent Be sites. In the first Be site, Be(1) is bonded in a 2-coordinate geometry to one Be(2) and two equivalent Be(1) atoms. The Be(1)-Be(2) bond length is 0.84 Å. Both Be(1)-Be(1) bond lengths are 0.49 Å. In the second Be site, Be(2) is bonded in a 4-coordinate geometry to three equivalent Be(1) and one Tl(1) atom. The Be(2)-Tl(1) bond length is 1.28 Å. Tl(1) is bonded in a linear geometry to one Sr(1) and one Be(2) atom.