data_YNb4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.23
_cell_length_b   8.23
_cell_length_c   8.23
_cell_angle_alpha   109.47
_cell_angle_beta   109.47
_cell_angle_gamma   109.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YNb4
_chemical_formula_sum   'Y4 Nb16'
_cell_volume   428.62
_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  Y16  1  0.57  0.43  0.43  1.0
  Y  Y17  1  0.32  0.32  0.32  1.0
  Y  Y18  1  0.43  0.43  0.57  1.0
  Y  Y19  1  0.43  0.57  0.43  1.0
  Nb  Nb0  1  0.22  0.78  0.78  1.0
  Nb  Nb1  1  0.97  0.97  0.97  1.0
  Nb  Nb2  1  0.78  0.78  0.22  1.0
  Nb  Nb3  1  0.78  0.22  0.78  1.0
  Nb  Nb4  1  0.0  0.0  0.33  1.0
  Nb  Nb5  1  0.0  0.0  0.17  1.0
  Nb  Nb6  1  0.0  0.33  0.0  1.0
  Nb  Nb7  1  0.0  0.17  0.0  1.0
  Nb  Nb8  1  0.17  0.0  0.0  1.0
  Nb  Nb9  1  0.33  0.0  0.0  1.0
  Nb  Nb10  1  0.0  0.75  0.37  1.0
  Nb  Nb11  1  0.75  0.0  0.37  1.0
  Nb  Nb12  1  0.75  0.37  0.0  1.0
  Nb  Nb13  1  0.0  0.37  0.75  1.0
  Nb  Nb14  1  0.37  0.75  0.0  1.0
  Nb  Nb15  1  0.37  0.0  0.75  1.0

data_YNb4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   13.43
_cell_length_b   13.43
_cell_length_c   8.23
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   YNb4
_chemical_formula_sum   'Y12 Nb48'
_cell_volume   1285.86
_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  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  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'
  10  '-y+2/3, -x+1/3, z+1/3'
  11  '-x+y+2/3, y+1/3, z+1/3'
  12  'x+2/3, x-y+1/3, z+1/3'
  13  'x+1/3, y+2/3, z+2/3'
  14  '-y+1/3, x-y+2/3, z+2/3'
  15  '-x+y+1/3, -x+2/3, z+2/3'
  16  '-y+1/3, -x+2/3, z+2/3'
  17  '-x+y+1/3, y+2/3, z+2/3'
  18  'x+1/3, x-y+2/3, z+2/3'
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  0.09  0.04  0.48  1.0
  Y  Y1  3  0.0  0.0  0.32  1.0
  Nb  Nb2  18  0.0  0.37  0.37  1.0
  Nb  Nb3  9  0.11  0.06  0.06  1.0
  Nb  Nb4  9  0.19  0.38  0.59  1.0
  Nb  Nb5  9  0.22  0.11  0.11  1.0
  Nb  Nb6  3  0.0  0.0  0.97  1.0

Y Y Y Y Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb
Y Y Y Y Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb Nb 0 1 o o o 0 3 o o o 0 2 o o o 1 3 o o o 1 2 o o o 2 3 o o o 4 18 o o + 4 19 o + o 4 13 o + + 5 11 + + + 5 12 + + + 5 9 + + + 6 15 o + o 6 14 + o o 6 8 + + o 7 16 o o + 7 17 + o o 7 10 + o + 8 9 o o o 8 14 o - o 8 15 - o o 10 11 o o o 10 16 - o o 10 17 o o - 12 13 o o o 13 18 o - o 13 19 o o - 
YNb4 crystallizes in the trigonal R3m space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 3-coordinate geometry to one Y(2), two equivalent Y(1), and two equivalent Nb(5) atoms. The Y(1)-Y(2) bond length is 1.68 Å. Both Y(1)-Y(1) bond lengths are 1.81 Å. Both Y(1)-Nb(5) bond lengths are 3.93 Å. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to three equivalent Y(1) and three equivalent Nb(4) atoms. All Y(2)-Nb(4) bond lengths are 2.52 Å. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 3-coordinate geometry to one Nb(3) and four equivalent Nb(5) atoms. The Nb(1)-Nb(3) bond length is 1.71 Å. There are two shorter (1.99 Å) and two longer (3.10 Å) Nb(1)-Nb(5) bond lengths. In the second Nb site, Nb(2) is bonded in a 3-coordinate geometry to three equivalent Nb(4) atoms. All Nb(2)-Nb(4) bond lengths are 1.53 Å. In the third Nb site, Nb(3) is bonded in a distorted water-like geometry to one Nb(1), one Nb(4), and two equivalent Nb(5) atoms. The Nb(3)-Nb(4) bond length is 1.27 Å. Both Nb(3)-Nb(5) bond lengths are 2.22 Å. In the fourth Nb site, Nb(4) is bonded in a 3-coordinate geometry to one Y(2), one Nb(2), and one Nb(3) atom. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to one Y(1), one Nb(3), two equivalent Nb(1), and two equivalent Nb(5) atoms. Both Nb(5)-Nb(5) bond lengths are 2.91 Å.