data_BeNb2Tl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.95
_cell_length_b   3.95
_cell_length_c   4.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeNb2Tl
_chemical_formula_sum   'Be1 Nb2 Tl1'
_cell_volume   68.66
_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
  Nb  Nb1  1  0.0  0.98  0.2  1.0
  Nb  Nb2  1  0.98  0.0  0.2  1.0
  Tl  Tl3  1  0.98  0.98  0.0  1.0

data_BeNb2Tl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.59
_cell_length_b   5.59
_cell_length_c   4.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BeNb2Tl
_chemical_formula_sum   'Be2 Nb4 Tl2'
_cell_volume   137.33
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.0  1.0
  Nb  Nb1  4  0.49  0.49  0.2  1.0
  Tl  Tl2  2  0.48  0.5  -0.0  1.0

Be Nb Nb Tl
BeTl(Nb)2 is alpha carbon monoxide-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two BeTl clusters and two Nb clusters. In each BeTl cluster, Be(1) is bonded in a single-bond geometry to one Tl(1) atom. The Be(1)-Tl(1) bond length is 0.14 Å. Tl(1) is bonded in a single-bond geometry to one Be(1) atom. In each Nb cluster, Nb(1) is bonded in a single-bond geometry to one Nb(1) atom. The Nb(1)-Nb(1) bond length is 0.14 Å.