data_LaNbSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.98
_cell_length_b   3.98
_cell_length_c   5.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   LaNbSe2
_chemical_formula_sum   'La1 Nb1 Se2'
_cell_volume   94.56
_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  0.99  0.99  0.59  1.0
  Nb  Nb1  1  0.0  0.0  0.82  1.0
  Se  Se2  1  0.99  0.99  0.5  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

data_LaNbSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.63
_cell_length_b   5.63
_cell_length_c   5.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   LaNbSe2
_chemical_formula_sum   'La2 Nb2 Se4'
_cell_volume   189.13
_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  0.49  0.5  0.59  1.0
  Nb  Nb1  2  0.0  0.0  0.82  1.0
  Se  Se2  2  0.0  0.0  0.0  1.0
  Se  Se3  2  0.49  0.5  0.5  1.0

La Nb Se Se
La Nb Se Se 0 2 o o o 1 3 o o + 
LaNbSe2 is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two LaNbSe2 clusters. La(1) is bonded in a distorted linear geometry to one Nb(1) and one Se(1) atom. The La(1)-Nb(1) bond length is 1.40 Å. The La(1)-Se(1) bond length is 0.53 Å. Nb(1) is bonded in a linear geometry to one La(1) and one Se(2) atom. The Nb(1)-Se(2) bond length is 1.08 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one La(1) atom. In the second Se site, Se(2) is bonded in a single-bond geometry to one Nb(1) atom.