data_Li2TaBe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.68
_cell_length_b   2.68
_cell_length_c   7.99
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2TaBe
_chemical_formula_sum   'Li2 Ta1 Be1'
_cell_volume   57.16
_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
  Li  Li1  1  0.34  0.34  0.68  1.0
  Li  Li2  1  0.34  0.34  0.31  1.0
  Ta  Ta3  1  0.0  0.0  0.99  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0

data_Li2TaBe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.78
_cell_length_b   3.78
_cell_length_c   7.99
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Li2TaBe
_chemical_formula_sum   'Li4 Ta2 Be2'
_cell_volume   114.32
_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
  Li  Li0  2  0.34  0.0  0.31  1.0
  Li  Li1  2  0.34  0.0  0.68  1.0
  Ta  Ta2  2  0.0  0.0  0.99  1.0
  Be  Be3  2  0.0  0.0  0.0  1.0

Li Li Ta Be
Li Li Ta Be 0 3 o o + 0 3 o + + 0 3 + o + 0 2 o o o 0 2 o + o 0 2 + o o 0 0 + o o 0 0 o + o 0 1 o o o 1 3 o o o 1 3 o + o 1 3 + o o 1 2 o o - 1 2 o + - 1 2 + o - 1 1 + o o 1 1 o + o 2 3 o o + 
Li2BeTa crystallizes in the monoclinic Cm space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 8-coordinate geometry to one Li(2), four equivalent Li(1), and three equivalent Ta(1) atoms. The Li(1)-Li(2) bond length is 2.99 Å. All Li(1)-Li(1) bond lengths are 2.68 Å. There is one shorter (2.80 Å) and two longer (3.19 Å) Li(1)-Ta(1) bond lengths. In the second Li site, Li(2) is bonded to one Li(1), four equivalent Li(2), and one Be(1) atom to form a mixture of distorted edge and corner-sharing LiLi5Be octahedra. The corner-sharing octahedra are not tilted. All Li(2)-Li(2) bond lengths are 2.68 Å. The Li(2)-Be(1) bond length is 2.75 Å. Be(1) is bonded in a single-bond geometry to one Li(2) and one Ta(1) atom. The Be(1)-Ta(1) bond length is 0.06 Å. Ta(1) is bonded in a single-bond geometry to three equivalent Li(1) and one Be(1) atom.