The compound described by Y3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(1), one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted YO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Y(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Y(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-50°. In the second Y site, Y(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(4), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Y(1)O7 pentagonal bipyramids, and edges with four equivalent Y(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(1) and two equivalent Ta(1) atoms to form distorted OY2Ta2 trigonal pyramids that share corners with two equivalent O(3)Y4 tetrahedra, corners with four equivalent O(4)Y3Ta tetrahedra, corners with two equivalent O(1)Y2Ta2 trigonal pyramids,  an edgeedge with one O(2)Y4 tetrahedra, and edges with two equivalent O(4)Y3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with four equivalent O(4)Y3Ta tetrahedra, corners with four equivalent O(3)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, edges with two equivalent O(4)Y3Ta tetrahedra, and  an edgeedge with one O(1)Y2Ta2 trigonal pyramid. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(3)Y4 tetrahedra, corners with four equivalent O(4)Y3Ta tetrahedra, corners with four equivalent O(2)Y4 tetrahedra, corners with two equivalent O(1)Y2Ta2 trigonal pyramids,  an edgeedge with one O(2)Y4 tetrahedra, and edges with two equivalent O(4)Y3Ta tetrahedra. In the fourth O site, O(4) is bonded to one Y(2), two equivalent Y(1), and one Ta(1) atom to form distorted OY3Ta tetrahedra that share corners with two equivalent O(4)Y3Ta tetrahedra, corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(1)Y2Ta2 trigonal pyramids,  an edgeedge with one O(4)Y3Ta tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, and  an edgeedge with one O(1)Y2Ta2 trigonal pyramid. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Y(2), two equivalent Y(1), and one Ta(1) atom. is represented by the CIF card [CIF]
data_Y3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.449
_cell_length_b   6.449
_cell_length_c   7.437
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   108.902
_symmetry_Int_Tables_number   1
_cell_volume   292.630
_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
  Y  Y0  1  1.000  0.535  0.242  1.0
  Y  Y1  1  0.000  0.465  0.742  1.0
  Y  Y2  1  0.535  1.000  0.758  1.0
  Y  Y3  1  0.465  0.000  0.258  1.0
  Y  Y4  1  0.469  0.469  0.000  1.0
  Y  Y5  1  0.531  0.531  0.500  1.0
  Ta  Ta6  1  0.998  0.998  0.000  1.0
  Ta  Ta7  1  0.002  0.002  0.500  1.0
  O  O8  1  0.933  0.067  0.750  1.0
  O  O9  1  0.067  0.933  0.250  1.0
  O  O10  1  0.361  0.639  0.250  1.0
  O  O11  1  0.639  0.361  0.750  1.0
  O  O12  1  0.371  0.629  0.750  1.0
  O  O13  1  0.629  0.371  0.250  1.0
  O  O14  1  0.328  0.082  0.976  1.0
  O  O15  1  0.672  0.918  0.476  1.0
  O  O16  1  0.310  0.053  0.542  1.0
  O  O17  1  0.690  0.947  0.042  1.0
  O  O18  1  0.053  0.310  0.458  1.0
  O  O19  1  0.947  0.690  0.958  1.0
  O  O20  1  0.918  0.672  0.524  1.0
  O  O21  1  0.082  0.328  0.024  1.0
[/CIF]
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The compound described by Y3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(1), one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted YO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Y(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Y(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-50°. In the second Y site, Y(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(4), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Y(1)O7 pentagonal bipyramids, and edges with four equivalent Y(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(1) and two equivalent Ta(1) atoms to form distorted OY2Ta2 trigonal pyramids that share corners with two equivalent O(3)Y4 tetrahedra, corners with four equivalent O(4)Y3Ta tetrahedra, corners with two equivalent O(1)Y2Ta2 trigonal pyramids,  an edgeedge with one O(2)Y4 tetrahedra, and edges with two equivalent O(4)Y3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with four equivalent O(4)Y3Ta tetrahedra, corners with four equivalent O(3)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, edges with two equivalent O(4)Y3Ta tetrahedra, and  an edgeedge with one O(1)Y2Ta2 trigonal pyramid. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(3)Y4 tetrahedra, corners with four equivalent O(4)Y3Ta tetrahedra, corners with four equivalent O(2)Y4 tetrahedra, corners with two equivalent O(1)Y2Ta2 trigonal pyramids,  an edgeedge with one O(2)Y4 tetrahedra, and edges with two equivalent O(4)Y3Ta tetrahedra. In the fourth O site, O(4) is bonded to one Y(2), two equivalent Y(1), and one Ta(1) atom to form distorted OY3Ta tetrahedra that share corners with two equivalent O(4)Y3Ta tetrahedra, corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(1)Y2Ta2 trigonal pyramids,  an edgeedge with one O(4)Y3Ta tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, and  an edgeedge with one O(1)Y2Ta2 trigonal pyramid. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Y(2), two equivalent Y(1), and one Ta(1) atom. is represented by the CIF card [CIF]
data_Y3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.449
_cell_length_b   6.449
_cell_length_c   7.437
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   108.902
_symmetry_Int_Tables_number   1
_cell_volume   292.630
_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
  Y  Y0  1  1.000  0.535  0.242  1.0
  Y  Y1  1  0.000  0.465  0.742  1.0
  Y  Y2  1  0.535  1.000  0.758  1.0
  Y  Y3  1  0.465  0.000  0.258  1.0
  Y  Y4  1  0.469  0.469  0.000  1.0
  Y  Y5  1  0.531  0.531  0.500  1.0
  Ta  Ta6  1  0.998  0.998  0.000  1.0
  Ta  Ta7  1  0.002  0.002  0.500  1.0
  O  O8  1  0.933  0.067  0.750  1.0
  O  O9  1  0.067  0.933  0.250  1.0
  O  O10  1  0.361  0.639  0.250  1.0
  O  O11  1  0.639  0.361  0.750  1.0
  O  O12  1  0.371  0.629  0.750  1.0
  O  O13  1  0.629  0.371  0.250  1.0
  O  O14  1  0.328  0.082  0.976  1.0
  O  O15  1  0.672  0.918  0.476  1.0
  O  O16  1  0.310  0.053  0.542  1.0
  O  O17  1  0.690  0.947  0.042  1.0
  O  O18  1  0.053  0.310  0.458  1.0
  O  O19  1  0.947  0.690  0.958  1.0
  O  O20  1  0.918  0.672  0.524  1.0
  O  O21  1  0.082  0.328  0.024  1.0
[/CIF]
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