Dy(CO2)4 crystallizes in the monoclinic P2_1/c space group. Dy(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Dy(1)-O(1) bond length is 2.39 Å. The Dy(1)-O(2) bond length is 2.39 Å. The Dy(1)-O(3) bond length is 2.44 Å. The Dy(1)-O(4) bond length is 2.44 Å. The Dy(1)-O(5) bond length is 2.47 Å. The Dy(1)-O(6) bond length is 2.43 Å. The Dy(1)-O(7) bond length is 2.45 Å. The Dy(1)-O(8) bond length is 2.39 Å. There are four inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(2) atom. The C(1)-O(1) bond length is 1.24 Å. The C(1)-O(2) bond length is 1.26 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(4) atom. The C(2)-O(3) bond length is 1.25 Å. The C(2)-O(4) bond length is 1.25 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(6) atom. The C(3)-O(5) bond length is 1.25 Å. The C(3)-O(6) bond length is 1.25 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(7) and one O(8) atom. The C(4)-O(7) bond length is 1.25 Å. The C(4)-O(8) bond length is 1.24 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Dy(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Dy(1) and one C(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Dy(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Dy(1) and one C(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Dy(1) and one C(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Dy(1) and one C(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Dy(1) and one C(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Dy(1) and one C(4) atom. Linkers: 7 [O]C(=O)C([O])=O. Metal clusters: 4 [Dy]. RCSR code: jeb. The MOF has largest included sphere 4.86 A, density 1.67 g/cm3, surface area 2219.21 m2/g, accessible volume 0.40 cm3/g