data_Nb4Sb3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.78
_cell_length_b   5.78
_cell_length_c   4.98
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb4Sb3
_chemical_formula_sum   'Nb4 Sb3'
_cell_volume   143.99
_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
  Nb  Nb0  1  0.0  0.0  0.74  1.0
  Nb  Nb1  1  0.0  0.0  0.24  1.0
  Nb  Nb2  1  0.0  0.34  0.0  1.0
  Nb  Nb3  1  0.89  0.67  0.0  1.0
  Sb  Sb4  1  0.44  0.5  0.49  1.0
  Sb  Sb5  1  0.89  0.0  0.49  1.0
  Sb  Sb6  1  0.56  0.5  0.49  1.0

data_Nb4Sb3
_symmetry_space_group_name_H-M   Pm
_cell_length_a   5.78
_cell_length_b   4.98
_cell_length_c   5.78
_cell_angle_alpha   90.0
_cell_angle_beta   120.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   Nb4Sb3
_chemical_formula_sum   'Nb4 Sb3'
_cell_volume   143.99
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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
  Nb  Nb0  2  0.0  0.25  0.0  1.0
  Nb  Nb1  1  0.0  0.0  0.34  1.0
  Nb  Nb2  1  0.89  0.0  0.67  1.0
  Sb  Sb3  1  0.44  0.5  0.5  1.0
  Sb  Sb4  1  0.56  0.5  0.5  1.0
  Sb  Sb5  1  0.89  0.5  0.0  1.0

Nb Nb Nb Nb Sb Sb Sb
Nb4Sb3 crystallizes in the triclinic P1 space group. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a single-bond geometry to one Nb(3), one Nb(4), and one Sb(2) atom. The Nb(1)-Nb(3) bond length is 2.33 Å. The Nb(1)-Nb(4) bond length is 2.13 Å. The Nb(1)-Sb(2) bond length is 1.40 Å. In the second Nb site, Nb(2) is bonded in a single-bond geometry to one Nb(3), one Nb(4), and one Sb(2) atom. The Nb(2)-Nb(3) bond length is 2.28 Å. The Nb(2)-Nb(4) bond length is 2.08 Å. The Nb(2)-Sb(2) bond length is 1.40 Å. In the third Nb site, Nb(3) is bonded in a 7-coordinate geometry to one Nb(1), one Nb(2), one Nb(4), two equivalent Sb(1), and two equivalent Sb(2) atoms. The Nb(3)-Nb(4) bond length is 2.31 Å. There is one shorter (3.32 Å) and one longer (3.39 Å) Nb(3)-Sb(1) bond length. There is one shorter (2.98 Å) and one longer (3.06 Å) Nb(3)-Sb(2) bond length. In the fourth Nb site, Nb(4) is bonded in a distorted pentagonal planar geometry to one Nb(1), one Nb(2), one Nb(3), and two equivalent Sb(3) atoms. There is one shorter (2.96 Å) and one longer (3.03 Å) Nb(4)-Sb(3) bond length. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a single-bond geometry to two equivalent Nb(3) and one Sb(3) atom. The Sb(1)-Sb(3) bond length is 0.65 Å. In the second Sb site, Sb(2) is bonded in a bent 120 degrees geometry to one Nb(1), one Nb(2), and two equivalent Nb(3) atoms. In the third Sb site, Sb(3) is bonded in a distorted single-bond geometry to two equivalent Nb(4) and one Sb(1) atom.