Dy3TaO7 crystallizes in the monoclinic Pc space group. There are three inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a distorted hexagonal planar geometry to one O(2), one O(4), one O(5), one O(7), and two equivalent O(1) atoms. In the second Dy site, Dy(2) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms. In the third Dy site, Dy(3) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(5), and two equivalent O(7) atoms. Ta(1) is bonded in a distorted body-centered cubic geometry to one O(2), one O(4), one O(5), one O(7), two equivalent O(3), and two equivalent O(6) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Dy(2), one Dy(3), and two equivalent Dy(1) atoms to form ODy4 tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(2)Dy3Ta tetrahedra,  an edgeedge with one O(4)Dy3Ta tetrahedra,  an edgeedge with one O(5)Dy3Ta tetrahedra, and  an edgeedge with one O(7)Dy3Ta tetrahedra. In the second O site, O(2) is bonded to one Dy(1), two equivalent Dy(2), and one Ta(1) atom to form ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(4)Dy3Ta tetrahedra. In the third O site, O(3) is bonded to one Dy(2), one Dy(3), and two equivalent Ta(1) atoms to form distorted ODy2Ta2 tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(2)Dy3Ta tetrahedra,  an edgeedge with one O(4)Dy3Ta tetrahedra,  an edgeedge with one O(5)Dy3Ta tetrahedra,  an edgeedge with one O(7)Dy3Ta tetrahedra, and edges with two equivalent O(6)Dy2Ta2 tetrahedra. In the fourth O site, O(4) is bonded to one Dy(1), two equivalent Dy(2), and one Ta(1) atom to form distorted ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(2)Dy3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Dy(1), two equivalent Dy(3), and one Ta(1) atom to form ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(7)Dy3Ta tetrahedra. In the sixth O site, O(6) is bonded to one Dy(2), one Dy(3), and two equivalent Ta(1) atoms to form distorted ODy2Ta2 tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(2)Dy3Ta tetrahedra,  an edgeedge with one O(4)Dy3Ta tetrahedra,  an edgeedge with one O(5)Dy3Ta tetrahedra,  an edgeedge with one O(7)Dy3Ta tetrahedra, and edges with two equivalent O(3)Dy2Ta2 tetrahedra. In the seventh O site, O(7) is bonded to one Dy(1), two equivalent Dy(3), and one Ta(1) atom to form distorted ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(5)Dy3Ta tetrahedra.
Dy3TaO7 crystallizes in the monoclinic Pc space group. There are three inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a distorted hexagonal planar geometry to one O(2), one O(4), one O(5), one O(7), and two equivalent O(1) atoms. The Dy(1)-O(2) bond length is 2.30 Å. The Dy(1)-O(4) bond length is 2.27 Å. The Dy(1)-O(5) bond length is 2.26 Å. The Dy(1)-O(7) bond length is 2.29 Å. There is one shorter (2.30 Å) and one longer (2.32 Å) Dy(1)-O(1) bond length. In the second Dy site, Dy(2) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms. The Dy(2)-O(1) bond length is 2.25 Å. The Dy(2)-O(3) bond length is 2.53 Å. The Dy(2)-O(6) bond length is 2.08 Å. There is one shorter (2.27 Å) and one longer (2.50 Å) Dy(2)-O(2) bond length. There is one shorter (2.28 Å) and one longer (2.52 Å) Dy(2)-O(4) bond length. In the third Dy site, Dy(3) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(5), and two equivalent O(7) atoms. The Dy(3)-O(1) bond length is 2.26 Å. The Dy(3)-O(3) bond length is 2.09 Å. The Dy(3)-O(6) bond length is 2.49 Å. There is one shorter (2.26 Å) and one longer (2.49 Å) Dy(3)-O(5) bond length. There is one shorter (2.30 Å) and one longer (2.50 Å) Dy(3)-O(7) bond length. Ta(1) is bonded in a distorted body-centered cubic geometry to one O(2), one O(4), one O(5), one O(7), two equivalent O(3), and two equivalent O(6) atoms. The Ta(1)-O(2) bond length is 2.14 Å. The Ta(1)-O(4) bond length is 2.14 Å. The Ta(1)-O(5) bond length is 2.16 Å. The Ta(1)-O(7) bond length is 2.13 Å. There is one shorter (2.02 Å) and one longer (2.43 Å) Ta(1)-O(3) bond length. There is one shorter (2.00 Å) and one longer (2.50 Å) Ta(1)-O(6) bond length. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Dy(2), one Dy(3), and two equivalent Dy(1) atoms to form ODy4 tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(2)Dy3Ta tetrahedra,  an edgeedge with one O(4)Dy3Ta tetrahedra,  an edgeedge with one O(5)Dy3Ta tetrahedra, and  an edgeedge with one O(7)Dy3Ta tetrahedra. In the second O site, O(2) is bonded to one Dy(1), two equivalent Dy(2), and one Ta(1) atom to form ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(4)Dy3Ta tetrahedra. In the third O site, O(3) is bonded to one Dy(2), one Dy(3), and two equivalent Ta(1) atoms to form distorted ODy2Ta2 tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(2)Dy3Ta tetrahedra,  an edgeedge with one O(4)Dy3Ta tetrahedra,  an edgeedge with one O(5)Dy3Ta tetrahedra,  an edgeedge with one O(7)Dy3Ta tetrahedra, and edges with two equivalent O(6)Dy2Ta2 tetrahedra. In the fourth O site, O(4) is bonded to one Dy(1), two equivalent Dy(2), and one Ta(1) atom to form distorted ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(2)Dy3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Dy(1), two equivalent Dy(3), and one Ta(1) atom to form ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(7)Dy3Ta tetrahedra. In the sixth O site, O(6) is bonded to one Dy(2), one Dy(3), and two equivalent Ta(1) atoms to form distorted ODy2Ta2 tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(2)Dy3Ta tetrahedra,  an edgeedge with one O(4)Dy3Ta tetrahedra,  an edgeedge with one O(5)Dy3Ta tetrahedra,  an edgeedge with one O(7)Dy3Ta tetrahedra, and edges with two equivalent O(3)Dy2Ta2 tetrahedra. In the seventh O site, O(7) is bonded to one Dy(1), two equivalent Dy(3), and one Ta(1) atom to form distorted ODy3Ta tetrahedra that share corners with two equivalent O(3)Dy2Ta2 tetrahedra, corners with two equivalent O(6)Dy2Ta2 tetrahedra, corners with two equivalent O(2)Dy3Ta tetrahedra, corners with two equivalent O(4)Dy3Ta tetrahedra, corners with two equivalent O(5)Dy3Ta tetrahedra, corners with two equivalent O(7)Dy3Ta tetrahedra, corners with two equivalent O(1)Dy4 tetrahedra,  an edgeedge with one O(3)Dy2Ta2 tetrahedra,  an edgeedge with one O(6)Dy2Ta2 tetrahedra,  an edgeedge with one O(1)Dy4 tetrahedra, and edges with two equivalent O(5)Dy3Ta tetrahedra.