Dy2Cu(WO4)4 crystallizes in the monoclinic C2/c space group. Dy(1) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and two equivalent O(8) atoms to form distorted DyO7 pentagonal bipyramids that share corners with three equivalent W(1)O6 octahedra, corners with four equivalent W(2)O6 octahedra,  an edgeedge with one W(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and  an edgeedge with one Dy(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 31-57°. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(2), one O(3), one O(4), one O(8), and two equivalent O(1) atoms to form distorted WO6 octahedra that share  a cornercorner with one Cu(1)O6 octahedra, corners with two equivalent W(1)O6 octahedra, corners with three equivalent Dy(1)O7 pentagonal bipyramids,  an edgeedge with one W(2)O6 octahedra, and  an edgeedge with one Dy(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 11-52°. In the second W site, W(2) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with three equivalent Cu(1)O6 octahedra, corners with four equivalent Dy(1)O7 pentagonal bipyramids,  an edgeedge with one W(1)O6 octahedra, and  an edgeedge with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-54°. Cu(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form CuO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with six equivalent W(2)O6 octahedra, and edges with two equivalent Dy(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 50-54°. There are eight inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to one Dy(1), one W(1), and one Cu(1) atom. In the second O site, O(3) is bonded in a trigonal planar geometry to one Dy(1), one W(1), and one W(2) atom. In the third O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Dy(1), one W(1), and one W(2) atom. In the fourth O site, O(5) is bonded in a trigonal planar geometry to two equivalent W(2) and one Cu(1) atom. In the fifth O site, O(6) is bonded in a distorted trigonal planar geometry to one Dy(1), one W(2), and one Cu(1) atom. In the sixth O site, O(7) is bonded in a bent 150 degrees geometry to one Dy(1) and one W(2) atom. In the seventh O site, O(8) is bonded in a trigonal non-coplanar geometry to two equivalent Dy(1) and one W(1) atom. In the eighth O site, O(1) is bonded in a linear geometry to two equivalent W(1) atoms.
Dy2Cu(WO4)4 crystallizes in the monoclinic C2/c space group. Dy(1) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and two equivalent O(8) atoms to form distorted DyO7 pentagonal bipyramids that share corners with three equivalent W(1)O6 octahedra, corners with four equivalent W(2)O6 octahedra,  an edgeedge with one W(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and  an edgeedge with one Dy(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 31-57°. The Dy(1)-O(2) bond length is 2.35 Å. The Dy(1)-O(3) bond length is 2.28 Å. The Dy(1)-O(4) bond length is 2.26 Å. The Dy(1)-O(6) bond length is 2.47 Å. The Dy(1)-O(7) bond length is 2.22 Å. There is one shorter (2.32 Å) and one longer (2.43 Å) Dy(1)-O(8) bond length. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(2), one O(3), one O(4), one O(8), and two equivalent O(1) atoms to form distorted WO6 octahedra that share  a cornercorner with one Cu(1)O6 octahedra, corners with two equivalent W(1)O6 octahedra, corners with three equivalent Dy(1)O7 pentagonal bipyramids,  an edgeedge with one W(2)O6 octahedra, and  an edgeedge with one Dy(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 11-52°. The W(1)-O(2) bond length is 1.85 Å. The W(1)-O(3) bond length is 1.99 Å. The W(1)-O(4) bond length is 2.08 Å. The W(1)-O(8) bond length is 1.90 Å. There is one shorter (1.83 Å) and one longer (2.20 Å) W(1)-O(1) bond length. In the second W site, W(2) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with three equivalent Cu(1)O6 octahedra, corners with four equivalent Dy(1)O7 pentagonal bipyramids,  an edgeedge with one W(1)O6 octahedra, and  an edgeedge with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-54°. The W(2)-O(3) bond length is 2.13 Å. The W(2)-O(4) bond length is 1.96 Å. The W(2)-O(6) bond length is 1.85 Å. The W(2)-O(7) bond length is 1.79 Å. There is one shorter (1.96 Å) and one longer (2.14 Å) W(2)-O(5) bond length. Cu(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form CuO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with six equivalent W(2)O6 octahedra, and edges with two equivalent Dy(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 50-54°. Both Cu(1)-O(2) bond lengths are 2.27 Å. Both Cu(1)-O(5) bond lengths are 2.17 Å. Both Cu(1)-O(6) bond lengths are 2.14 Å. There are eight inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to one Dy(1), one W(1), and one Cu(1) atom. In the second O site, O(3) is bonded in a trigonal planar geometry to one Dy(1), one W(1), and one W(2) atom. In the third O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Dy(1), one W(1), and one W(2) atom. In the fourth O site, O(5) is bonded in a trigonal planar geometry to two equivalent W(2) and one Cu(1) atom. In the fifth O site, O(6) is bonded in a distorted trigonal planar geometry to one Dy(1), one W(2), and one Cu(1) atom. In the sixth O site, O(7) is bonded in a bent 150 degrees geometry to one Dy(1) and one W(2) atom. In the seventh O site, O(8) is bonded in a trigonal non-coplanar geometry to two equivalent Dy(1) and one W(1) atom. In the eighth O site, O(1) is bonded in a linear geometry to two equivalent W(1) atoms.