data_SrBeTlCd
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   5.19
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrBeTlCd
_chemical_formula_sum   'Sr1 Be1 Tl1 Cd1'
_cell_volume   99.0
_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  Sr2  1  0.84  0.84  0.84  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Tl  Tl3  1  0.51  0.51  0.51  1.0
  Cd  Cd1  1  0.67  0.67  0.67  1.0

data_SrBeTlCd
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   12.72
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrBeTlCd
_chemical_formula_sum   'Sr3 Be3 Tl3 Cd3'
_cell_volume   297.0
_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  0.16  1.0
  Be  Be1  3  0.0  0.0  0.0  1.0
  Tl  Tl2  3  0.0  0.0  0.49  1.0
  Cd  Cd3  3  0.0  0.0  0.33  1.0

Sr Be Tl Cd
Sr Be Tl Cd 0 3 o o o 0 1 + + + 2 3 o o o 
SrBeCdTl crystallizes in the trigonal R3m space group. Sr(1) is bonded to one Be(1), one Cd(1), and three equivalent Tl(1) atoms to form distorted SrBeTl3Cd trigonal bipyramids that share corners with six equivalent Sr(1)BeTl3Cd trigonal bipyramids and  a cornercorner with one Tl(1)Sr3Cd trigonal pyramid. The Sr(1)-Be(1) bond length is 2.09 Å. The Sr(1)-Cd(1) bond length is 2.09 Å. All Sr(1)-Tl(1) bond lengths are 3.00 Å. Be(1) is bonded in a single-bond geometry to one Sr(1) atom. Cd(1) is bonded in a 1-coordinate geometry to one Sr(1) and one Tl(1) atom. The Cd(1)-Tl(1) bond length is 2.09 Å. Tl(1) is bonded to three equivalent Sr(1) and one Cd(1) atom to form TlSr3Cd trigonal pyramids that share  a cornercorner with one Sr(1)BeTl3Cd trigonal bipyramid and corners with six equivalent Tl(1)Sr3Cd trigonal pyramids.