Dy2W2O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), one O(7), one O(9), and two equivalent O(3) atoms. In the second Dy site, Dy(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(9), two equivalent O(7), and two equivalent O(8) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing WO6 octahedra. In the second W site, W(2) is bonded to one O(2), one O(5), one O(7), one O(8), and one O(9) atom to form corner-sharing WO5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 44-54°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Dy(1), one Dy(2), and one W(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Dy(1), one Dy(2), one W(1), and one W(2) atom. In the third O site, O(3) is bonded to one Dy(2), two equivalent Dy(1), and one W(1) atom to form a mixture of corner and edge-sharing ODy3W trigonal pyramids. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Dy(1), one Dy(2), and one W(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Dy(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Dy(1) and one W(1) atom. In the seventh O site, O(7) is bonded to one Dy(1), two equivalent Dy(2), and one W(2) atom to form a mixture of distorted corner and edge-sharing ODy3W tetrahedra. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Dy(2) and one W(2) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Dy(1), one Dy(2), and one W(2) atom.
Dy2W2O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), one O(7), one O(9), and two equivalent O(3) atoms. The Dy(1)-O(1) bond length is 2.30 Å. The Dy(1)-O(2) bond length is 2.48 Å. The Dy(1)-O(4) bond length is 2.50 Å. The Dy(1)-O(5) bond length is 2.38 Å. The Dy(1)-O(6) bond length is 2.35 Å. The Dy(1)-O(7) bond length is 2.48 Å. The Dy(1)-O(9) bond length is 2.61 Å. There is one shorter (2.37 Å) and one longer (2.44 Å) Dy(1)-O(3) bond length. In the second Dy site, Dy(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(9), two equivalent O(7), and two equivalent O(8) atoms. The Dy(2)-O(1) bond length is 2.48 Å. The Dy(2)-O(2) bond length is 2.61 Å. The Dy(2)-O(3) bond length is 2.39 Å. The Dy(2)-O(4) bond length is 2.35 Å. The Dy(2)-O(9) bond length is 2.48 Å. There is one shorter (2.49 Å) and one longer (2.51 Å) Dy(2)-O(7) bond length. There is one shorter (2.51 Å) and one longer (2.56 Å) Dy(2)-O(8) bond length. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing WO6 octahedra. The W(1)-O(1) bond length is 1.84 Å. The W(1)-O(2) bond length is 2.18 Å. The W(1)-O(3) bond length is 2.01 Å. The W(1)-O(4) bond length is 1.84 Å. The W(1)-O(5) bond length is 2.10 Å. The W(1)-O(6) bond length is 1.83 Å. In the second W site, W(2) is bonded to one O(2), one O(5), one O(7), one O(8), and one O(9) atom to form corner-sharing WO5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 44-54°. The W(2)-O(2) bond length is 1.93 Å. The W(2)-O(5) bond length is 1.94 Å. The W(2)-O(7) bond length is 1.94 Å. The W(2)-O(8) bond length is 1.84 Å. The W(2)-O(9) bond length is 1.84 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Dy(1), one Dy(2), and one W(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Dy(1), one Dy(2), one W(1), and one W(2) atom. In the third O site, O(3) is bonded to one Dy(2), two equivalent Dy(1), and one W(1) atom to form a mixture of corner and edge-sharing ODy3W trigonal pyramids. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Dy(1), one Dy(2), and one W(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Dy(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Dy(1) and one W(1) atom. In the seventh O site, O(7) is bonded to one Dy(1), two equivalent Dy(2), and one W(2) atom to form a mixture of distorted corner and edge-sharing ODy3W tetrahedra. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Dy(2) and one W(2) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Dy(1), one Dy(2), and one W(2) atom.