The crystal structure described by Gd3NbO7 crystallizes in the triclinic P-1 space group. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(3), one O(4), one O(7), two equivalent O(2), and two equivalent O(6) atoms to form distorted GdO7 pentagonal bipyramids that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Gd(3)O7 pentagonal bipyramid,  an edgeedge with one Nb(1)O6 octahedra, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 47-50°. In the second Gd site, Gd(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(6), two equivalent O(4), and two equivalent O(7) atoms. In the third Gd site, Gd(3) is bonded to one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form distorted GdO7 pentagonal bipyramids that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Gd(1)O7 pentagonal bipyramid,  an edgeedge with one Nb(1)O6 octahedra,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-45°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Gd(1)O7 pentagonal bipyramids, corners with two equivalent Gd(3)O7 pentagonal bipyramids, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. In the second Nb site, Nb(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Gd(1)O7 pentagonal bipyramids, corners with two equivalent Gd(3)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Gd(2), two equivalent Gd(3), and one Nb(2) atom to form distorted OGd3Nb trigonal pyramids that share  a cornercorner with one O(6)Gd4 tetrahedra, corners with two equivalent O(4)Gd3Nb tetrahedra, corners with two equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(3)Gd3Nb tetrahedra,  a cornercorner with one O(1)Gd3Nb trigonal pyramid,  an edgeedge with one O(4)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Nb(1) atom. In the third O site, O(3) is bonded to one Gd(1), two equivalent Gd(3), and one Nb(1) atom to form distorted OGd3Nb tetrahedra that share  a cornercorner with one O(3)Gd3Nb tetrahedra,  a cornercorner with one O(4)Gd3Nb tetrahedra,  a cornercorner with one O(7)Gd4 tetrahedra, corners with two equivalent O(6)Gd4 tetrahedra, corners with four equivalent O(1)Gd3Nb trigonal pyramids,  an edgeedge with one O(3)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra, and  an edgeedge with one O(7)Gd4 tetrahedra. In the fourth O site, O(4) is bonded to one Gd(1), two equivalent Gd(2), and one Nb(2) atom to form distorted OGd3Nb tetrahedra that share  a cornercorner with one O(3)Gd3Nb tetrahedra,  a cornercorner with one O(4)Gd3Nb tetrahedra, corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(6)Gd4 tetrahedra, corners with two equivalent O(1)Gd3Nb trigonal pyramids,  an edgeedge with one O(4)Gd3Nb tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Gd(3), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded to one Gd(2), one Gd(3), and two equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with two equivalent O(3)Gd3Nb tetrahedra, corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(4)Gd3Nb tetrahedra,  a cornercorner with one O(1)Gd3Nb trigonal pyramid,  an edgeedge with one O(3)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the seventh O site, O(7) is bonded to one Gd(1), one Gd(3), and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share  a cornercorner with one O(3)Gd3Nb tetrahedra, corners with three equivalent O(4)Gd3Nb tetrahedra, corners with three equivalent O(6)Gd4 tetrahedra, corners with two equivalent O(1)Gd3Nb trigonal pyramids,  an edgeedge with one O(3)Gd3Nb tetrahedra,  an edgeedge with one O(4)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. is represented by the CIF card [CIF]
data_Gd3NbO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.433
_cell_length_b   6.530
_cell_length_c   7.657
_cell_angle_alpha   106.886
_cell_angle_beta   89.786
_cell_angle_gamma   97.536
_symmetry_Int_Tables_number   1
_cell_volume   304.904
_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
  Gd  Gd0  1  0.738  0.464  0.117  1.0
  Gd  Gd1  1  0.739  0.462  0.611  1.0
  Gd  Gd2  1  0.545  0.993  0.749  1.0
  Gd  Gd3  1  0.455  0.007  0.251  1.0
  Gd  Gd4  1  0.261  0.538  0.389  1.0
  Gd  Gd5  1  0.262  0.536  0.883  1.0
  Nb  Nb6  1  0.000  0.000  0.000  1.0
  Nb  Nb7  1  0.000  0.000  0.500  1.0
  O  O8  1  0.710  0.069  0.484  1.0
  O  O9  1  0.922  0.679  0.948  1.0
  O  O10  1  0.709  0.071  0.050  1.0
  O  O11  1  0.925  0.670  0.394  1.0
  O  O12  1  0.913  0.954  0.738  1.0
  O  O13  1  0.558  0.351  0.835  1.0
  O  O14  1  0.543  0.362  0.342  1.0
  O  O15  1  0.457  0.638  0.658  1.0
  O  O16  1  0.442  0.649  0.165  1.0
  O  O17  1  0.087  0.046  0.262  1.0
  O  O18  1  0.075  0.330  0.606  1.0
  O  O19  1  0.291  0.929  0.950  1.0
  O  O20  1  0.078  0.321  0.052  1.0
  O  O21  1  0.290  0.931  0.516  1.0
[/CIF]
.
The crystal structure described by Gd3NbO7 crystallizes in the triclinic P-1 space group. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(3), one O(4), one O(7), two equivalent O(2), and two equivalent O(6) atoms to form distorted GdO7 pentagonal bipyramids that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Gd(3)O7 pentagonal bipyramid,  an edgeedge with one Nb(1)O6 octahedra, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 47-50°. In the second Gd site, Gd(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(6), two equivalent O(4), and two equivalent O(7) atoms. In the third Gd site, Gd(3) is bonded to one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form distorted GdO7 pentagonal bipyramids that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Gd(1)O7 pentagonal bipyramid,  an edgeedge with one Nb(1)O6 octahedra,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-45°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Gd(1)O7 pentagonal bipyramids, corners with two equivalent Gd(3)O7 pentagonal bipyramids, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. In the second Nb site, Nb(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Gd(1)O7 pentagonal bipyramids, corners with two equivalent Gd(3)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Gd(2), two equivalent Gd(3), and one Nb(2) atom to form distorted OGd3Nb trigonal pyramids that share  a cornercorner with one O(6)Gd4 tetrahedra, corners with two equivalent O(4)Gd3Nb tetrahedra, corners with two equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(3)Gd3Nb tetrahedra,  a cornercorner with one O(1)Gd3Nb trigonal pyramid,  an edgeedge with one O(4)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Nb(1) atom. In the third O site, O(3) is bonded to one Gd(1), two equivalent Gd(3), and one Nb(1) atom to form distorted OGd3Nb tetrahedra that share  a cornercorner with one O(3)Gd3Nb tetrahedra,  a cornercorner with one O(4)Gd3Nb tetrahedra,  a cornercorner with one O(7)Gd4 tetrahedra, corners with two equivalent O(6)Gd4 tetrahedra, corners with four equivalent O(1)Gd3Nb trigonal pyramids,  an edgeedge with one O(3)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra, and  an edgeedge with one O(7)Gd4 tetrahedra. In the fourth O site, O(4) is bonded to one Gd(1), two equivalent Gd(2), and one Nb(2) atom to form distorted OGd3Nb tetrahedra that share  a cornercorner with one O(3)Gd3Nb tetrahedra,  a cornercorner with one O(4)Gd3Nb tetrahedra, corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(6)Gd4 tetrahedra, corners with two equivalent O(1)Gd3Nb trigonal pyramids,  an edgeedge with one O(4)Gd3Nb tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Gd(3), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded to one Gd(2), one Gd(3), and two equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with two equivalent O(3)Gd3Nb tetrahedra, corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(4)Gd3Nb tetrahedra,  a cornercorner with one O(1)Gd3Nb trigonal pyramid,  an edgeedge with one O(3)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the seventh O site, O(7) is bonded to one Gd(1), one Gd(3), and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share  a cornercorner with one O(3)Gd3Nb tetrahedra, corners with three equivalent O(4)Gd3Nb tetrahedra, corners with three equivalent O(6)Gd4 tetrahedra, corners with two equivalent O(1)Gd3Nb trigonal pyramids,  an edgeedge with one O(3)Gd3Nb tetrahedra,  an edgeedge with one O(4)Gd3Nb tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. is represented by the CIF card [CIF]
data_Gd3NbO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.433
_cell_length_b   6.530
_cell_length_c   7.657
_cell_angle_alpha   106.886
_cell_angle_beta   89.786
_cell_angle_gamma   97.536
_symmetry_Int_Tables_number   1
_cell_volume   304.904
_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
  Gd  Gd0  1  0.738  0.464  0.117  1.0
  Gd  Gd1  1  0.739  0.462  0.611  1.0
  Gd  Gd2  1  0.545  0.993  0.749  1.0
  Gd  Gd3  1  0.455  0.007  0.251  1.0
  Gd  Gd4  1  0.261  0.538  0.389  1.0
  Gd  Gd5  1  0.262  0.536  0.883  1.0
  Nb  Nb6  1  0.000  0.000  0.000  1.0
  Nb  Nb7  1  0.000  0.000  0.500  1.0
  O  O8  1  0.710  0.069  0.484  1.0
  O  O9  1  0.922  0.679  0.948  1.0
  O  O10  1  0.709  0.071  0.050  1.0
  O  O11  1  0.925  0.670  0.394  1.0
  O  O12  1  0.913  0.954  0.738  1.0
  O  O13  1  0.558  0.351  0.835  1.0
  O  O14  1  0.543  0.362  0.342  1.0
  O  O15  1  0.457  0.638  0.658  1.0
  O  O16  1  0.442  0.649  0.165  1.0
  O  O17  1  0.087  0.046  0.262  1.0
  O  O18  1  0.075  0.330  0.606  1.0
  O  O19  1  0.291  0.929  0.950  1.0
  O  O20  1  0.078  0.321  0.052  1.0
  O  O21  1  0.290  0.931  0.516  1.0
[/CIF]
.