data_La2NbSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.6
_cell_length_b   5.6
_cell_length_c   5.6
_cell_angle_alpha   130.1
_cell_angle_beta   130.1
_cell_angle_gamma   73.24
_symmetry_Int_Tables_number   1
_chemical_formula_structural   La2NbSi
_chemical_formula_sum   'La2 Nb1 Si1'
_cell_volume   100.24
_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  0.36  0.0  0.25  1.0
  La  La1  1  0.0  0.36  0.25  1.0
  Nb  Nb2  1  0.0  0.0  0.49  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0

data_La2NbSi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.68
_cell_length_b   6.68
_cell_length_c   5.6
_cell_angle_alpha   90.0
_cell_angle_beta   126.62
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   La2NbSi
_chemical_formula_sum   'La4 Nb2 Si2'
_cell_volume   200.48
_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  4  0.32  0.32  0.89  1.0
  Nb  Nb1  2  0.0  0.0  0.49  1.0
  Si  Si2  2  0.0  0.0  0.0  1.0

La La Nb Si
La2NbSi crystallizes in the monoclinic Cm space group. La(1) is bonded in a single-bond geometry to one Nb(1) and one Si(1) atom. The La(1)-Nb(1) bond length is 2.89 Å. The La(1)-Si(1) bond length is 1.55 Å. Nb(1) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Si(1) atoms. There is one shorter (2.76 Å) and one longer (2.84 Å) Nb(1)-Si(1) bond length. Si(1) is bonded in a water-like geometry to two equivalent La(1) and two equivalent Nb(1) atoms.