The compound described by Y3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. In the second Y site, Y(2) is bonded to one O(2), one O(3), one O(4), and four equivalent O(1) atoms to form distorted YO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Y(2)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Y(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 46°. Ta(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Y(2)O7 pentagonal bipyramids, and edges with four equivalent Y(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Y(1), two equivalent Y(2), and one Ta(1) atom. In the second O site, O(2) is bonded to two equivalent Y(2) and two equivalent Ta(1) atoms to form distorted OY2Ta2 trigonal pyramids that share corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(2)Y2Ta2 trigonal pyramids, and  an edgeedge with one O(4)Y4 tetrahedra. 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)Y4 tetrahedra, corners with two equivalent O(2)Y2Ta2 trigonal pyramids, and  an edgeedge with one O(4)Y4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(4)Y4 tetrahedra, corners with four equivalent O(3)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, and  an edgeedge with one O(2)Y2Ta2 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.419
_cell_length_b   6.419
_cell_length_c   7.471
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   109.597
_symmetry_Int_Tables_number   1
_cell_volume   290.029
_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  0.500  0.500  0.500  1.0
  Y  Y1  1  0.500  0.500  0.000  1.0
  Y  Y2  1  0.534  0.000  0.750  1.0
  Y  Y3  1  0.000  0.534  0.250  1.0
  Y  Y4  1  0.466  1.000  0.250  1.0
  Y  Y5  1  1.000  0.466  0.750  1.0
  Ta  Ta6  1  0.000  0.000  0.500  1.0
  Ta  Ta7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.678  0.927  0.468  1.0
  O  O9  1  0.927  0.678  0.532  1.0
  O  O10  1  0.678  0.927  0.032  1.0
  O  O11  1  0.927  0.678  0.968  1.0
  O  O12  1  0.322  0.073  0.532  1.0
  O  O13  1  0.073  0.322  0.468  1.0
  O  O14  1  0.322  0.073  0.968  1.0
  O  O15  1  0.073  0.322  0.032  1.0
  O  O16  1  0.934  0.066  0.750  1.0
  O  O17  1  0.066  0.934  0.250  1.0
  O  O18  1  0.371  0.629  0.750  1.0
  O  O19  1  0.629  0.371  0.250  1.0
  O  O20  1  0.638  0.362  0.750  1.0
  O  O21  1  0.362  0.638  0.250  1.0
[/CIF]
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The compound described by Y3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. In the second Y site, Y(2) is bonded to one O(2), one O(3), one O(4), and four equivalent O(1) atoms to form distorted YO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Y(2)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Y(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 46°. Ta(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Y(2)O7 pentagonal bipyramids, and edges with four equivalent Y(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Y(1), two equivalent Y(2), and one Ta(1) atom. In the second O site, O(2) is bonded to two equivalent Y(2) and two equivalent Ta(1) atoms to form distorted OY2Ta2 trigonal pyramids that share corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(2)Y2Ta2 trigonal pyramids, and  an edgeedge with one O(4)Y4 tetrahedra. 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)Y4 tetrahedra, corners with two equivalent O(2)Y2Ta2 trigonal pyramids, and  an edgeedge with one O(4)Y4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(4)Y4 tetrahedra, corners with four equivalent O(3)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, and  an edgeedge with one O(2)Y2Ta2 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.419
_cell_length_b   6.419
_cell_length_c   7.471
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   109.597
_symmetry_Int_Tables_number   1
_cell_volume   290.029
_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  0.500  0.500  0.500  1.0
  Y  Y1  1  0.500  0.500  0.000  1.0
  Y  Y2  1  0.534  0.000  0.750  1.0
  Y  Y3  1  0.000  0.534  0.250  1.0
  Y  Y4  1  0.466  1.000  0.250  1.0
  Y  Y5  1  1.000  0.466  0.750  1.0
  Ta  Ta6  1  0.000  0.000  0.500  1.0
  Ta  Ta7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.678  0.927  0.468  1.0
  O  O9  1  0.927  0.678  0.532  1.0
  O  O10  1  0.678  0.927  0.032  1.0
  O  O11  1  0.927  0.678  0.968  1.0
  O  O12  1  0.322  0.073  0.532  1.0
  O  O13  1  0.073  0.322  0.468  1.0
  O  O14  1  0.322  0.073  0.968  1.0
  O  O15  1  0.073  0.322  0.032  1.0
  O  O16  1  0.934  0.066  0.750  1.0
  O  O17  1  0.066  0.934  0.250  1.0
  O  O18  1  0.371  0.629  0.750  1.0
  O  O19  1  0.629  0.371  0.250  1.0
  O  O20  1  0.638  0.362  0.750  1.0
  O  O21  1  0.362  0.638  0.250  1.0
[/CIF]
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