The crystal structure described by Dy3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(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 DyO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Dy(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Dy(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 39-50°. In the second Dy site, Dy(2) is bonded in a 6-coordinate geometry to two equivalent O(2), 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 Dy(1)O7 pentagonal bipyramids, and edges with four equivalent Dy(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 42°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Dy(1) and two equivalent Ta(1) atoms to form distorted ODy2Ta2 trigonal pyramids that share corners with two equivalent O(4)Dy4 tetrahedra, corners with four equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy2Ta2 trigonal pyramids,  an edgeedge with one O(2)Dy4 tetrahedra, and edges with two equivalent O(5)Dy3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Dy(1) and two equivalent Dy(2) atoms to form ODy4 tetrahedra that share corners with two equivalent O(2)Dy4 tetrahedra, corners with four equivalent O(5)Dy3Ta tetrahedra, corners with four equivalent O(4)Dy4 tetrahedra,  an edgeedge with one O(4)Dy4 tetrahedra, edges with two equivalent O(5)Dy3Ta tetrahedra, and  an edgeedge with one O(1)Dy2Ta2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Dy(1) and one Ta(1) atom. In the fourth O site, O(4) is bonded to two equivalent Dy(1) and two equivalent Dy(2) atoms to form ODy4 tetrahedra that share corners with two equivalent O(4)Dy4 tetrahedra, corners with four equivalent O(5)Dy3Ta tetrahedra, corners with four equivalent O(2)Dy4 tetrahedra, corners with two equivalent O(1)Dy2Ta2 trigonal pyramids,  an edgeedge with one O(2)Dy4 tetrahedra, and edges with two equivalent O(5)Dy3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Dy(2), two equivalent Dy(1), and one Ta(1) atom to form distorted ODy3Ta tetrahedra that share corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(2)Dy4 tetrahedra, corners with two equivalent O(4)Dy4 tetrahedra, corners with two equivalent O(1)Dy2Ta2 trigonal pyramids,  an edgeedge with one O(5)Dy3Ta tetrahedra,  an edgeedge with one O(2)Dy4 tetrahedra,  an edgeedge with one O(4)Dy4 tetrahedra, and  an edgeedge with one O(1)Dy2Ta2 trigonal pyramid. is represented by the CIF file [CIF]
data_Dy3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.444
_cell_length_b   6.444
_cell_length_c   7.423
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   108.796
_symmetry_Int_Tables_number   1
_cell_volume   291.769
_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
  Dy  Dy0  1  1.000  0.535  0.241  1.0
  Dy  Dy1  1  0.465  0.000  0.259  1.0
  Dy  Dy2  1  0.466  0.466  0.000  1.0
  Dy  Dy3  1  0.534  0.534  0.500  1.0
  Dy  Dy4  1  0.000  0.465  0.741  1.0
  Dy  Dy5  1  0.535  1.000  0.759  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  0.932  0.068  0.750  1.0
  O  O9  1  0.639  0.361  0.750  1.0
  O  O10  1  0.309  0.052  0.544  1.0
  O  O11  1  0.948  0.691  0.956  1.0
  O  O12  1  0.629  0.371  0.250  1.0
  O  O13  1  0.917  0.672  0.524  1.0
  O  O14  1  0.328  0.083  0.976  1.0
  O  O15  1  0.083  0.328  0.024  1.0
  O  O16  1  0.672  0.917  0.476  1.0
  O  O17  1  0.371  0.629  0.750  1.0
  O  O18  1  0.691  0.948  0.044  1.0
  O  O19  1  0.052  0.309  0.456  1.0
  O  O20  1  0.361  0.639  0.250  1.0
  O  O21  1  0.068  0.932  0.250  1.0
[/CIF]
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The crystal structure described by Dy3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(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 DyO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Dy(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Dy(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 39-50°. In the second Dy site, Dy(2) is bonded in a 6-coordinate geometry to two equivalent O(2), 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 Dy(1)O7 pentagonal bipyramids, and edges with four equivalent Dy(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 42°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Dy(1) and two equivalent Ta(1) atoms to form distorted ODy2Ta2 trigonal pyramids that share corners with two equivalent O(4)Dy4 tetrahedra, corners with four equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy2Ta2 trigonal pyramids,  an edgeedge with one O(2)Dy4 tetrahedra, and edges with two equivalent O(5)Dy3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Dy(1) and two equivalent Dy(2) atoms to form ODy4 tetrahedra that share corners with two equivalent O(2)Dy4 tetrahedra, corners with four equivalent O(5)Dy3Ta tetrahedra, corners with four equivalent O(4)Dy4 tetrahedra,  an edgeedge with one O(4)Dy4 tetrahedra, edges with two equivalent O(5)Dy3Ta tetrahedra, and  an edgeedge with one O(1)Dy2Ta2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Dy(1) and one Ta(1) atom. In the fourth O site, O(4) is bonded to two equivalent Dy(1) and two equivalent Dy(2) atoms to form ODy4 tetrahedra that share corners with two equivalent O(4)Dy4 tetrahedra, corners with four equivalent O(5)Dy3Ta tetrahedra, corners with four equivalent O(2)Dy4 tetrahedra, corners with two equivalent O(1)Dy2Ta2 trigonal pyramids,  an edgeedge with one O(2)Dy4 tetrahedra, and edges with two equivalent O(5)Dy3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Dy(2), two equivalent Dy(1), and one Ta(1) atom to form distorted ODy3Ta tetrahedra that share corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(2)Dy4 tetrahedra, corners with two equivalent O(4)Dy4 tetrahedra, corners with two equivalent O(1)Dy2Ta2 trigonal pyramids,  an edgeedge with one O(5)Dy3Ta tetrahedra,  an edgeedge with one O(2)Dy4 tetrahedra,  an edgeedge with one O(4)Dy4 tetrahedra, and  an edgeedge with one O(1)Dy2Ta2 trigonal pyramid. is represented by the CIF file [CIF]
data_Dy3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.444
_cell_length_b   6.444
_cell_length_c   7.423
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   108.796
_symmetry_Int_Tables_number   1
_cell_volume   291.769
_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
  Dy  Dy0  1  1.000  0.535  0.241  1.0
  Dy  Dy1  1  0.465  0.000  0.259  1.0
  Dy  Dy2  1  0.466  0.466  0.000  1.0
  Dy  Dy3  1  0.534  0.534  0.500  1.0
  Dy  Dy4  1  0.000  0.465  0.741  1.0
  Dy  Dy5  1  0.535  1.000  0.759  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  0.932  0.068  0.750  1.0
  O  O9  1  0.639  0.361  0.750  1.0
  O  O10  1  0.309  0.052  0.544  1.0
  O  O11  1  0.948  0.691  0.956  1.0
  O  O12  1  0.629  0.371  0.250  1.0
  O  O13  1  0.917  0.672  0.524  1.0
  O  O14  1  0.328  0.083  0.976  1.0
  O  O15  1  0.083  0.328  0.024  1.0
  O  O16  1  0.672  0.917  0.476  1.0
  O  O17  1  0.371  0.629  0.750  1.0
  O  O18  1  0.691  0.948  0.044  1.0
  O  O19  1  0.052  0.309  0.456  1.0
  O  O20  1  0.361  0.639  0.250  1.0
  O  O21  1  0.068  0.932  0.250  1.0
[/CIF]
.