The compound described by Gd3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Gd(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-49°. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Gd(1)O7 pentagonal bipyramids, and edges with four equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Gd(1) and two equivalent Ta(1) atoms to form distorted OGd2Ta2 trigonal pyramids that share corners with two equivalent O(4)Gd4 tetrahedra, corners with four equivalent O(5)Gd3Ta tetrahedra, corners with two equivalent O(1)Gd2Ta2 trigonal pyramids,  an edgeedge with one O(2)Gd4 tetrahedra, and edges with two equivalent O(5)Gd3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Gd(1) and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with two equivalent O(2)Gd4 tetrahedra, corners with four equivalent O(5)Gd3Ta tetrahedra, corners with four equivalent O(4)Gd4 tetrahedra,  an edgeedge with one O(4)Gd4 tetrahedra, edges with two equivalent O(5)Gd3Ta tetrahedra, and  an edgeedge with one O(1)Gd2Ta2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Ta(1) atom. In the fourth O site, O(4) is bonded to two equivalent Gd(1) and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with two equivalent O(4)Gd4 tetrahedra, corners with four equivalent O(5)Gd3Ta tetrahedra, corners with four equivalent O(2)Gd4 tetrahedra, corners with two equivalent O(1)Gd2Ta2 trigonal pyramids,  an edgeedge with one O(2)Gd4 tetrahedra, and edges with two equivalent O(5)Gd3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Gd(2), two equivalent Gd(1), and one Ta(1) atom to form distorted OGd3Ta tetrahedra that share corners with two equivalent O(5)Gd3Ta tetrahedra, corners with two equivalent O(2)Gd4 tetrahedra, corners with two equivalent O(4)Gd4 tetrahedra, corners with two equivalent O(1)Gd2Ta2 trigonal pyramids,  an edgeedge with one O(5)Gd3Ta tetrahedra,  an edgeedge with one O(2)Gd4 tetrahedra,  an edgeedge with one O(4)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd2Ta2 trigonal pyramid. is represented by the CIF file [CIF]
data_Gd3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.530
_cell_length_b   6.530
_cell_length_c   7.532
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   109.085
_symmetry_Int_Tables_number   1
_cell_volume   303.515
_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  0.465  0.001  0.257  1.0
  Gd  Gd1  1  0.999  0.535  0.243  1.0
  Gd  Gd2  1  0.470  0.470  0.000  1.0
  Gd  Gd3  1  0.530  0.530  0.500  1.0
  Gd  Gd4  1  0.535  0.999  0.757  1.0
  Gd  Gd5  1  0.001  0.465  0.743  1.0
  Ta  Ta6  1  0.002  0.002  0.500  1.0
  Ta  Ta7  1  0.998  0.998  0.000  1.0
  O  O8  1  0.937  0.063  0.750  1.0
  O  O9  1  0.638  0.362  0.750  1.0
  O  O10  1  0.307  0.053  0.540  1.0
  O  O11  1  0.947  0.693  0.960  1.0
  O  O12  1  0.629  0.371  0.250  1.0
  O  O13  1  0.919  0.676  0.525  1.0
  O  O14  1  0.324  0.081  0.975  1.0
  O  O15  1  0.081  0.324  0.025  1.0
  O  O16  1  0.676  0.919  0.475  1.0
  O  O17  1  0.371  0.629  0.750  1.0
  O  O18  1  0.693  0.947  0.040  1.0
  O  O19  1  0.053  0.307  0.460  1.0
  O  O20  1  0.362  0.638  0.250  1.0
  O  O21  1  0.063  0.937  0.250  1.0
[/CIF]
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The compound described by Gd3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Gd(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-49°. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Gd(1)O7 pentagonal bipyramids, and edges with four equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Gd(1) and two equivalent Ta(1) atoms to form distorted OGd2Ta2 trigonal pyramids that share corners with two equivalent O(4)Gd4 tetrahedra, corners with four equivalent O(5)Gd3Ta tetrahedra, corners with two equivalent O(1)Gd2Ta2 trigonal pyramids,  an edgeedge with one O(2)Gd4 tetrahedra, and edges with two equivalent O(5)Gd3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Gd(1) and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with two equivalent O(2)Gd4 tetrahedra, corners with four equivalent O(5)Gd3Ta tetrahedra, corners with four equivalent O(4)Gd4 tetrahedra,  an edgeedge with one O(4)Gd4 tetrahedra, edges with two equivalent O(5)Gd3Ta tetrahedra, and  an edgeedge with one O(1)Gd2Ta2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Ta(1) atom. In the fourth O site, O(4) is bonded to two equivalent Gd(1) and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with two equivalent O(4)Gd4 tetrahedra, corners with four equivalent O(5)Gd3Ta tetrahedra, corners with four equivalent O(2)Gd4 tetrahedra, corners with two equivalent O(1)Gd2Ta2 trigonal pyramids,  an edgeedge with one O(2)Gd4 tetrahedra, and edges with two equivalent O(5)Gd3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Gd(2), two equivalent Gd(1), and one Ta(1) atom to form distorted OGd3Ta tetrahedra that share corners with two equivalent O(5)Gd3Ta tetrahedra, corners with two equivalent O(2)Gd4 tetrahedra, corners with two equivalent O(4)Gd4 tetrahedra, corners with two equivalent O(1)Gd2Ta2 trigonal pyramids,  an edgeedge with one O(5)Gd3Ta tetrahedra,  an edgeedge with one O(2)Gd4 tetrahedra,  an edgeedge with one O(4)Gd4 tetrahedra, and  an edgeedge with one O(1)Gd2Ta2 trigonal pyramid. is represented by the CIF file [CIF]
data_Gd3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.530
_cell_length_b   6.530
_cell_length_c   7.532
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   109.085
_symmetry_Int_Tables_number   1
_cell_volume   303.515
_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  0.465  0.001  0.257  1.0
  Gd  Gd1  1  0.999  0.535  0.243  1.0
  Gd  Gd2  1  0.470  0.470  0.000  1.0
  Gd  Gd3  1  0.530  0.530  0.500  1.0
  Gd  Gd4  1  0.535  0.999  0.757  1.0
  Gd  Gd5  1  0.001  0.465  0.743  1.0
  Ta  Ta6  1  0.002  0.002  0.500  1.0
  Ta  Ta7  1  0.998  0.998  0.000  1.0
  O  O8  1  0.937  0.063  0.750  1.0
  O  O9  1  0.638  0.362  0.750  1.0
  O  O10  1  0.307  0.053  0.540  1.0
  O  O11  1  0.947  0.693  0.960  1.0
  O  O12  1  0.629  0.371  0.250  1.0
  O  O13  1  0.919  0.676  0.525  1.0
  O  O14  1  0.324  0.081  0.975  1.0
  O  O15  1  0.081  0.324  0.025  1.0
  O  O16  1  0.676  0.919  0.475  1.0
  O  O17  1  0.371  0.629  0.750  1.0
  O  O18  1  0.693  0.947  0.040  1.0
  O  O19  1  0.053  0.307  0.460  1.0
  O  O20  1  0.362  0.638  0.250  1.0
  O  O21  1  0.063  0.937  0.250  1.0
[/CIF]
.