data_Li2Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.02
_cell_length_b   8.02
_cell_length_c   4.98
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   161.72
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2Nb
_chemical_formula_sum   'Li4 Nb2'
_cell_volume   100.35
_cell_formula_units_Z   2
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  Li0  1  0.27  0.52  0.74  1.0
  Li  Li1  1  0.27  0.91  0.74  1.0
  Li  Li2  1  0.27  0.48  0.25  1.0
  Li  Li3  1  0.27  0.09  0.25  1.0
  Nb  Nb4  1  0.27  0.28  0.74  1.0
  Nb  Nb5  1  0.27  0.72  0.25  1.0

data_Li2Nb
_symmetry_space_group_name_H-M   P2_1/m
_cell_length_a   2.55
_cell_length_b   4.98
_cell_length_c   8.02
_cell_angle_alpha   90.0
_cell_angle_beta   99.14
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   11
_chemical_formula_structural   Li2Nb
_chemical_formula_sum   'Li4 Nb2'
_cell_volume   100.35
_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, y+1/2, -z'
  4  'x, -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  0.09  0.25  0.09  1.0
  Li  Li1  2  0.48  0.25  0.48  1.0
  Nb  Nb2  2  0.28  0.75  0.28  1.0

Li Li Li Li Nb Nb
Li Li Li Li Nb Nb 0 4 o o o 0 1 o o o 1 1 + + o 1 3 o + o 1 3 o + + 1 4 o + o 1 5 o o o 1 5 o o + 2 5 o o o 2 3 o o o 3 3 + + o 3 4 o o - 3 4 o o o 3 5 o - o 