data_La2Ta
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.48
_cell_length_b   8.48
_cell_length_c   8.48
_cell_angle_alpha   157.75
_cell_angle_beta   157.75
_cell_angle_gamma   31.68
_symmetry_Int_Tables_number   1
_chemical_formula_structural   La2Ta
_chemical_formula_sum   'La2 Ta1'
_cell_volume   87.26
_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
  La  La0  1  0.0  0.0  0.48  1.0
  La  La1  1  0.0  0.0  0.83  1.0
  Ta  Ta2  1  0.0  0.0  0.0  1.0

data_La2Ta
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.63
_cell_length_b   4.63
_cell_length_c   8.48
_cell_angle_alpha   90.0
_cell_angle_beta   105.84
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   La2Ta
_chemical_formula_sum   'La4 Ta2'
_cell_volume   174.52
_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
  La  La0  2  0.0  0.0  0.17  1.0
  La  La1  2  0.0  0.0  0.52  1.0
  Ta  Ta2  2  0.0  0.0  0.0  1.0

La La Ta
La2Ta crystallizes in the monoclinic Cm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to one La(2), four equivalent La(1), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing LaLa5Ta octahedra. The corner-sharing octahedra are not tilted. The La(1)-La(2) bond length is 3.00 Å. All La(1)-La(1) bond lengths are 3.27 Å. The La(1)-Ta(1) bond length is 4.04 Å. In the second La site, La(2) is bonded in a single-bond geometry to one La(1) and one Ta(1) atom. The La(2)-Ta(1) bond length is 1.43 Å. Ta(1) is bonded in a single-bond geometry to one La(1) and one La(2) atom.