GdC16H9O9 crystallizes in the monoclinic P2_1/c space group. Gd(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. The Gd(1)-O(1) bond length is 2.34 Å. The Gd(1)-O(2) bond length is 2.39 Å. The Gd(1)-O(4) bond length is 2.42 Å. The Gd(1)-O(6) bond length is 2.49 Å. The Gd(1)-O(7) bond length is 2.33 Å. The Gd(1)-O(8) bond length is 2.31 Å. The Gd(1)-O(9) bond length is 2.56 Å. There is one shorter (2.57 Å) and one longer (2.62 Å) Gd(1)-O(3) bond length. There are sixteen inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one C(7) atom. The C(1)-C(2) bond length is 1.41 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-C(7) bond length is 1.50 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(8) atom. The C(2)-C(3) bond length is 1.41 Å. The C(2)-C(8) bond length is 1.49 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2) and one H(1) atom. The C(3)-H(1) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(5) and one H(2) atom. The C(4)-C(5) bond length is 1.41 Å. The C(4)-H(2) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(12), one C(4), and one C(6) atom. The C(5)-C(12) bond length is 1.48 Å. The C(5)-C(6) bond length is 1.40 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(3) atom. The C(6)-H(3) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(7)-O(1) bond length is 1.27 Å. The C(7)-O(2) bond length is 1.28 Å. In the eighth C site, C(8) is bonded in a bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.30 Å. The C(8)-O(4) bond length is 1.26 Å. In the ninth C site, C(9) is bonded in a trigonal planar geometry to one C(10), one C(14), and one C(15) atom. The C(9)-C(10) bond length is 1.41 Å. The C(9)-C(14) bond length is 1.40 Å. The C(9)-C(15) bond length is 1.48 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(11), one C(16), and one C(9) atom. The C(10)-C(11) bond length is 1.40 Å. The C(10)-C(16) bond length is 1.51 Å. In the eleventh C site, C(11) is bonded in a distorted single-bond geometry to one C(10), one C(12), and one H(4) atom. The C(11)-C(12) bond length is 1.41 Å. The C(11)-H(4) bond length is 1.09 Å. In the twelfth C site, C(12) is bonded in a trigonal planar geometry to one C(11), one C(13), and one C(5) atom. The C(12)-C(13) bond length is 1.41 Å. In the thirteenth C site, C(13) is bonded in a distorted single-bond geometry to one C(12) and one H(5) atom. The C(13)-H(5) bond length is 1.09 Å. In the fourteenth C site, C(14) is bonded in a distorted single-bond geometry to one C(9) and one H(6) atom. The C(14)-H(6) bond length is 1.09 Å. In the fifteenth C site, C(15) is bonded in a distorted bent 120 degrees geometry to one C(9), one O(5), and one O(6) atom. The C(15)-O(5) bond length is 1.32 Å. The C(15)-O(6) bond length is 1.25 Å. In the sixteenth C site, C(16) is bonded in a distorted bent 120 degrees geometry to one C(10), one O(7), and one O(8) atom. The C(16)-O(7) bond length is 1.26 Å. The C(16)-O(8) bond length is 1.27 Å. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(6) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(11) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(13) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(14) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(9) atom. The H(7)-O(9) bond length is 0.99 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(2) and one O(9) atom. The H(8)-O(2) bond length is 1.69 Å. The H(8)-O(9) bond length is 1.01 Å. In the ninth H site, H(9) is bonded in a linear geometry to one O(5) and one O(9) atom. The H(9)-O(5) bond length is 1.02 Å. The H(9)-O(9) bond length is 1.61 Å. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a distorted linear geometry to one Gd(1) and one C(16) atom. In the second O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one C(16) atom. In the third O site, O(9) is bonded in a distorted water-like geometry to one Gd(1), one H(7), one H(8), and one H(9) atom. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one C(7) atom. In the fifth O site, O(2) is bonded in a distorted single-bond geometry to one Gd(1), one C(7), and one H(8) atom. In the sixth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Gd(1) and one C(8) atom. In the seventh O site, O(4) is bonded in a distorted single-bond geometry to one Gd(1) and one C(8) atom. In the eighth O site, O(5) is bonded in a water-like geometry to one C(15) and one H(9) atom. In the ninth O site, O(6) is bonded in a distorted single-bond geometry to one Gd(1) and one C(15) atom. Linkers: 4 [O]C(=O)c1ccc(-c2ccc(C(=O)O)c(C([O])=O)c2)cc1C([O])=O. Metal clusters: 4 [Gd]. The MOF has largest included sphere 1.53 A, density 2.48 g/cm3, surface area 2368.74 m2/g, accessible volume 0.04 cm3/g