The compound described by Y3TaO7 crystallizes in the orthorhombic Cmme space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(3), and four equivalent O(1) atoms. In the second Y site, Y(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted corner-sharing YO6 octahedra. The corner-sharing octahedral tilt angles are 70°. Ta(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Y(2), two equivalent Y(1), and one Ta(1) atom to form OY3Ta tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with four equivalent O(3)Y2Ta2 tetrahedra, corners with eight equivalent O(1)Y3Ta tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra, edges with two equivalent O(3)Y2Ta2 tetrahedra, and edges with two equivalent O(1)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(3)Y2Ta2 tetrahedra, corners with eight equivalent O(1)Y3Ta tetrahedra, and edges with four equivalent O(1)Y3Ta tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Ta(1) atoms to form distorted OY2Ta2 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with four equivalent O(3)Y2Ta2 tetrahedra, corners with eight equivalent O(1)Y3Ta tetrahedra, edges with two equivalent O(3)Y2Ta2 tetrahedra, and edges with four equivalent O(1)Y3Ta tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.167
_cell_length_b   8.167
_cell_length_c   5.375
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   125.508
_symmetry_Int_Tables_number   1
_cell_volume   291.821
_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  0.381  0.619  0.972  1.0
  Y  Y1  1  0.881  0.119  0.028  1.0
  Y  Y2  1  0.000  0.500  0.500  1.0
  Y  Y3  1  0.119  0.881  0.972  1.0
  Y  Y4  1  0.500  0.000  0.500  1.0
  Y  Y5  1  0.619  0.381  0.028  1.0
  Ta  Ta6  1  0.250  0.250  0.500  1.0
  Ta  Ta7  1  0.750  0.750  0.500  1.0
  O  O8  1  0.600  0.838  0.264  1.0
  O  O9  1  0.162  0.400  0.264  1.0
  O  O10  1  0.100  0.338  0.736  1.0
  O  O11  1  0.250  0.750  0.743  1.0
  O  O12  1  0.662  0.900  0.736  1.0
  O  O13  1  0.338  0.100  0.264  1.0
  O  O14  1  0.750  0.250  0.257  1.0
  O  O15  1  0.488  0.512  0.712  1.0
  O  O16  1  0.838  0.600  0.736  1.0
  O  O17  1  0.900  0.662  0.264  1.0
  O  O18  1  0.988  0.012  0.288  1.0
  O  O19  1  0.012  0.988  0.712  1.0
  O  O20  1  0.400  0.162  0.736  1.0
  O  O21  1  0.512  0.488  0.288  1.0
[/CIF]
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The compound described by Y3TaO7 crystallizes in the orthorhombic Cmme space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(3), and four equivalent O(1) atoms. In the second Y site, Y(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted corner-sharing YO6 octahedra. The corner-sharing octahedral tilt angles are 70°. Ta(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Y(2), two equivalent Y(1), and one Ta(1) atom to form OY3Ta tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with four equivalent O(3)Y2Ta2 tetrahedra, corners with eight equivalent O(1)Y3Ta tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra, edges with two equivalent O(3)Y2Ta2 tetrahedra, and edges with two equivalent O(1)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(3)Y2Ta2 tetrahedra, corners with eight equivalent O(1)Y3Ta tetrahedra, and edges with four equivalent O(1)Y3Ta tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Ta(1) atoms to form distorted OY2Ta2 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with four equivalent O(3)Y2Ta2 tetrahedra, corners with eight equivalent O(1)Y3Ta tetrahedra, edges with two equivalent O(3)Y2Ta2 tetrahedra, and edges with four equivalent O(1)Y3Ta tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.167
_cell_length_b   8.167
_cell_length_c   5.375
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   125.508
_symmetry_Int_Tables_number   1
_cell_volume   291.821
_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  0.381  0.619  0.972  1.0
  Y  Y1  1  0.881  0.119  0.028  1.0
  Y  Y2  1  0.000  0.500  0.500  1.0
  Y  Y3  1  0.119  0.881  0.972  1.0
  Y  Y4  1  0.500  0.000  0.500  1.0
  Y  Y5  1  0.619  0.381  0.028  1.0
  Ta  Ta6  1  0.250  0.250  0.500  1.0
  Ta  Ta7  1  0.750  0.750  0.500  1.0
  O  O8  1  0.600  0.838  0.264  1.0
  O  O9  1  0.162  0.400  0.264  1.0
  O  O10  1  0.100  0.338  0.736  1.0
  O  O11  1  0.250  0.750  0.743  1.0
  O  O12  1  0.662  0.900  0.736  1.0
  O  O13  1  0.338  0.100  0.264  1.0
  O  O14  1  0.750  0.250  0.257  1.0
  O  O15  1  0.488  0.512  0.712  1.0
  O  O16  1  0.838  0.600  0.736  1.0
  O  O17  1  0.900  0.662  0.264  1.0
  O  O18  1  0.988  0.012  0.288  1.0
  O  O19  1  0.012  0.988  0.712  1.0
  O  O20  1  0.400  0.162  0.736  1.0
  O  O21  1  0.512  0.488  0.288  1.0
[/CIF]
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