data_NbB3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.83
_cell_length_b   4.83
_cell_length_c   7.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NbB3
_chemical_formula_sum   'Nb4 B12'
_cell_volume   141.71
_cell_formula_units_Z   4
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  Nb12  1  0.0  0.0  0.51  1.0
  Nb  Nb13  1  0.0  0.0  0.0  1.0
  Nb  Nb14  1  0.42  0.39  0.26  1.0
  Nb  Nb15  1  0.0  0.79  0.75  1.0
  B  B0  1  0.79  0.09  0.51  1.0
  B  B1  1  0.79  0.09  0.0  1.0
  B  B2  1  0.21  0.09  0.51  1.0
  B  B3  1  0.42  0.0  0.51  1.0
  B  B4  1  0.42  0.0  0.0  1.0
  B  B5  1  0.21  0.09  0.0  1.0
  B  B6  1  0.87  0.29  0.26  1.0
  B  B7  1  0.55  0.89  0.75  1.0
  B  B8  1  0.13  0.29  0.26  1.0
  B  B9  1  0.0  0.79  0.26  1.0
  B  B10  1  0.42  0.4  0.75  1.0
  B  B11  1  0.28  0.89  0.75  1.0

data_NbB3
_symmetry_space_group_name_H-M   Pm
_cell_length_a   4.83
_cell_length_b   7.01
_cell_length_c   4.83
_cell_angle_alpha   90.0
_cell_angle_beta   120.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   NbB3
_chemical_formula_sum   'Nb4 B12'
_cell_volume   141.71
_cell_formula_units_Z   4
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  0.79  1.0
  Nb  Nb2  1  0.42  0.5  0.39  1.0
  B  B3  2  0.21  0.25  0.09  1.0
  B  B4  2  0.42  0.25  0.0  1.0
  B  B5  2  0.79  0.25  0.09  1.0
  B  B6  1  0.0  0.5  0.79  1.0
  B  B7  1  0.13  0.5  0.29  1.0
  B  B8  1  0.28  0.0  0.89  1.0
  B  B9  1  0.42  0.0  0.4  1.0
  B  B10  1  0.55  0.0  0.89  1.0
  B  B11  1  0.87  0.5  0.29  1.0

Nb Nb Nb Nb B B B B B B B B B B B B
NbB3 crystallizes in the triclinic P1 space group. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 2-coordinate geometry to one B(1); one B(10); and one B(3,6) atom. The Nb(1)-B(1) bond length is 1.28 Å. The Nb(1)-B(10) bond length is 2.01 Å. The Nb(1)-B(3,6) bond length is 0.87 Å. In the second Nb site, Nb(2) is bonded in a 2-coordinate geometry to one B(10); one B(2); and one B(3,6) atom. The Nb(2)-B(10) bond length is 2.09 Å. The Nb(2)-B(2) bond length is 1.28 Å. The Nb(2)-B(3,6) bond length is 0.87 Å. In the third Nb site, Nb(3) is bonded in a single-bond geometry to one B(10), one B(7), and one B(9) atom. The Nb(3)-B(10) bond length is 2.49 Å. The Nb(3)-B(7) bond length is 2.48 Å. The Nb(3)-B(9) bond length is 1.20 Å. In the fourth Nb site, Nb(4) is bonded in a single-bond geometry to one B(11) and one B(12) atom. The Nb(4)-B(11) bond length is 2.49 Å. The Nb(4)-B(12) bond length is 1.20 Å. There are ten inequivalent B sites. In the first B site, B(1) is bonded in a single-bond geometry to one Nb(1) and one B(7) atom. The B(1)-B(7) bond length is 1.92 Å. In the second B site, B(2) is bonded in a single-bond geometry to one Nb(2) and one B(7) atom. The B(2)-B(7) bond length is 2.00 Å. In the third B site, B(3,6) is bonded in a single-bond geometry to one Nb(1); one B(11); and one B(4,5) atom. The B(3,6)-B(11) bond length is 2.17 Å. The B(3,6)-B(4,5) bond length is 1.28 Å. In the fourth B site, B(4,5) is bonded in a 1-coordinate geometry to one B(3,6) atom. In the fifth B site, B(7) is bonded in a 5-coordinate geometry to one Nb(3), one B(1), one B(10), one B(2), and one B(9) atom. The B(7)-B(10) bond length is 2.16 Å. The B(7)-B(9) bond length is 1.28 Å. In the sixth B site, B(8) is bonded in a distorted single-bond geometry to one B(11) and one B(12) atom. The B(8)-B(11) bond length is 2.16 Å. The B(8)-B(12) bond length is 1.28 Å. In the seventh B site, B(9) is bonded in a distorted single-bond geometry to one Nb(3), one B(10), and one B(7) atom. The B(9)-B(10) bond length is 2.18 Å. In the eighth B site, B(10) is bonded in a 5-coordinate geometry to one Nb(1), one Nb(2), one Nb(3), one B(7), and one B(9) atom. In the ninth B site, B(11) is bonded in a 5-coordinate geometry to one Nb(4); one B(12); one B(8); and two equivalent B(3,6) atoms. The B(11)-B(12) bond length is 2.18 Å. In the tenth B site, B(12) is bonded in a distorted single-bond geometry to one Nb(4), one B(11), and one B(8) atom.