data_Ta2BeSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.13
_cell_length_b   5.13
_cell_length_c   5.13
_cell_angle_alpha   136.74
_cell_angle_beta   136.74
_cell_angle_gamma   62.84
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2BeSe
_chemical_formula_sum   'Ta2 Be1 Se1'
_cell_volume   62.74
_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
  Ta  Ta2  1  0.0  0.0  0.38  1.0
  Ta  Ta3  1  0.0  0.89  0.19  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.89  0.0  0.19  1.0

data_Ta2BeSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.78
_cell_length_b   3.78
_cell_length_c   5.13
_cell_angle_alpha   111.63
_cell_angle_beta   111.63
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2BeSe
_chemical_formula_sum   'Ta2 Be1 Se1'
_cell_volume   62.74
_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
  Ta  Ta0  1  0.3  0.19  0.3  1.0
  Ta  Ta1  1  0.38  0.38  0.38  1.0
  Be  Be2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.19  0.3  0.3  1.0

Ta Ta Be Se
BeTa2Se crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one BeTa2Se cluster. Be(1) is bonded in a 2-coordinate geometry to one Ta(2) and one Se(1) atom. The Be(1)-Ta(2) bond length is 1.43 Å. The Be(1)-Se(1) bond length is 1.43 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted single-bond geometry to one Se(1) atom. The Ta(1)-Se(1) bond length is 0.69 Å. In the second Ta site, Ta(2) is bonded in a single-bond geometry to one Be(1) and one Se(1) atom. The Ta(2)-Se(1) bond length is 0.58 Å. Se(1) is bonded in a 1-coordinate geometry to one Be(1), one Ta(1), and one Ta(2) atom.