data_Y2BeTl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   5.17
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Y2BeTl
_chemical_formula_sum   'Y2 Be1 Tl1'
_cell_volume   97.89
_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
  Y  Y2  1  0.66  0.66  0.66  1.0
  Y  Y3  1  0.83  0.83  0.83  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Tl  Tl1  1  0.49  0.49  0.49  1.0

data_Y2BeTl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   12.67
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Y2BeTl
_chemical_formula_sum   'Y6 Be3 Tl3'
_cell_volume   293.67
_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
  Y  Y0  3  0.0  0.0  0.17  1.0
  Y  Y1  3  0.0  0.0  0.34  1.0
  Be  Be2  3  0.0  0.0  0.0  1.0
  Tl  Tl3  3  0.0  0.0  0.51  1.0

Y Y Be Tl
Y Y Be Tl 0 3 o o o 0 1 o o o 1 2 + + + 
BeY2Tl crystallizes in the trigonal R3m space group. Be(1) is bonded to one Y(2) and three equivalent Y(1) atoms to form distorted BeY4 trigonal pyramids that share  a cornercorner with one Y(1)YBe3Tl trigonal bipyramid, corners with three equivalent Y(2)YBeTl3 trigonal bipyramids, corners with six equivalent Be(1)Y4 trigonal pyramids, and edges with three equivalent Tl(1)Y4 trigonal pyramids. The Be(1)-Y(2) bond length is 2.17 Å. All Be(1)-Y(1) bond lengths are 2.99 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to three equivalent Be(1), one Y(2), and one Tl(1) atom to form distorted YYBe3Tl trigonal bipyramids that share corners with six equivalent Y(1)YBe3Tl trigonal bipyramids,  a cornercorner with one Be(1)Y4 trigonal pyramid, corners with three equivalent Tl(1)Y4 trigonal pyramids, and edges with three equivalent Y(2)YBeTl3 trigonal bipyramids. The Y(1)-Y(2) bond length is 2.17 Å. The Y(1)-Tl(1) bond length is 2.17 Å. In the second Y site, Y(2) is bonded to one Be(1), one Y(1), and three equivalent Tl(1) atoms to form distorted YYBeTl3 trigonal bipyramids that share corners with six equivalent Y(2)YBeTl3 trigonal bipyramids,  a cornercorner with one Tl(1)Y4 trigonal pyramid, corners with three equivalent Be(1)Y4 trigonal pyramids, and edges with three equivalent Y(1)YBe3Tl trigonal bipyramids. All Y(2)-Tl(1) bond lengths are 2.99 Å. Tl(1) is bonded to one Y(1) and three equivalent Y(2) atoms to form distorted TlY4 trigonal pyramids that share  a cornercorner with one Y(2)YBeTl3 trigonal bipyramid, corners with three equivalent Y(1)YBe3Tl trigonal bipyramids, corners with six equivalent Tl(1)Y4 trigonal pyramids, and edges with three equivalent Be(1)Y4 trigonal pyramids.