data_YNb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.76
_cell_length_b   5.76
_cell_length_c   5.76
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YNb
_chemical_formula_sum   'Y4 Nb4'
_cell_volume   190.97
_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
  Y  Y4  1  0.56  0.56  0.56  1.0
  Y  Y5  1  0.32  0.19  0.44  1.0
  Y  Y6  1  0.19  0.44  0.32  1.0
  Y  Y7  1  0.44  0.32  0.19  1.0
  Nb  Nb0  1  0.28  0.28  0.28  1.0
  Nb  Nb1  1  0.59  0.47  0.16  1.0
  Nb  Nb2  1  0.47  0.16  0.59  1.0
  Nb  Nb3  1  0.16  0.59  0.47  1.0

data_YNb
_symmetry_space_group_name_H-M   R3
_cell_length_a   8.14
_cell_length_b   8.14
_cell_length_c   9.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   YNb
_chemical_formula_sum   'Y12 Nb12'
_cell_volume   572.9
_cell_formula_units_Z   12
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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
  Y  Y0  9  0.13  0.12  0.32  1.0
  Y  Y1  3  0.0  0.0  0.56  1.0
  Nb  Nb2  9  0.06  0.82  0.41  1.0
  Nb  Nb3  3  0.0  0.0  0.28  1.0

Y Y Y Y Nb Nb Nb Nb
YNb crystallizes in the trigonal R3 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 6-coordinate geometry to six equivalent Nb(2) atoms. There are three shorter (2.37 Å) and three longer (3.50 Å) Y(1)-Nb(2) bond lengths. In the second Y site, Y(2) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one Nb(2) atom. The Y(2)-Nb(1) bond length is 1.06 Å. The Y(2)-Nb(2) bond length is 1.28 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a trigonal non-coplanar geometry to three equivalent Y(2) atoms. In the second Nb site, Nb(2) is bonded in a distorted single-bond geometry to one Y(2) and two equivalent Y(1) atoms.