(Gd2C18H6(SO4)3)2H2O2 crystallizes in the monoclinic P2_1/c space group. The structure consists of four water molecules inside a Gd2C18H6(SO4)3 framework. In the Gd2C18H6(SO4)3 framework, there are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(1), one O(11), one O(6), one O(7), one O(8), and two equivalent O(12) atoms to form distorted edge-sharing GdO7 pentagonal bipyramids. The Gd(1)-O(1) bond length is 2.31 Å. The Gd(1)-O(11) bond length is 2.44 Å. The Gd(1)-O(6) bond length is 2.32 Å. The Gd(1)-O(7) bond length is 2.35 Å. The Gd(1)-O(8) bond length is 2.36 Å. There is one shorter (2.40 Å) and one longer (2.59 Å) Gd(1)-O(12) bond length. In the second Gd site, Gd(2) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(4), one O(5), and one O(9) atom. The Gd(2)-O(10) bond length is 2.39 Å. The Gd(2)-O(2) bond length is 2.35 Å. The Gd(2)-O(3) bond length is 2.38 Å. The Gd(2)-O(4) bond length is 2.30 Å. The Gd(2)-O(5) bond length is 2.34 Å. The Gd(2)-O(9) bond length is 2.35 Å. There are eighteen inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.48 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.24 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one S(1) atom. The C(2)-C(3) bond length is 1.33 Å. The C(2)-S(1) bond length is 1.72 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 0.95 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 1.36 Å. The C(4)-H(2) bond length is 0.95 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one S(1) atom. The C(5)-C(6) bond length is 1.48 Å. The C(5)-S(1) bond length is 1.72 Å. In the sixth C site, C(6) is bonded in a bent 120 degrees geometry to one C(5), one O(3), and one O(4) atom. The C(6)-O(3) bond length is 1.26 Å. The C(6)-O(4) bond length is 1.26 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(5), and one O(6) atom. The C(7)-C(8) bond length is 1.50 Å. The C(7)-O(5) bond length is 1.26 Å. The C(7)-O(6) bond length is 1.24 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(7), one C(9), and one S(2) atom. The C(8)-C(9) bond length is 1.35 Å. The C(8)-S(2) bond length is 1.72 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(8) and one H(3) atom. The C(9)-H(3) bond length is 0.95 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(11) and one H(4) atom. The C(10)-C(11) bond length is 1.36 Å. The C(10)-H(4) bond length is 0.95 Å. In the eleventh C site, C(11) is bonded in a trigonal planar geometry to one C(10), one C(12), and one S(2) atom. The C(11)-C(12) bond length is 1.47 Å. The C(11)-S(2) bond length is 1.72 Å. In the twelfth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(11), one O(7), and one O(8) atom. The C(12)-O(7) bond length is 1.24 Å. The C(12)-O(8) bond length is 1.29 Å. In the thirteenth C site, C(13) is bonded in a distorted bent 120 degrees geometry to one C(14), one O(10), and one O(9) atom. The C(13)-C(14) bond length is 1.49 Å. The C(13)-O(10) bond length is 1.26 Å. The C(13)-O(9) bond length is 1.25 Å. In the fourteenth C site, C(14) is bonded in a trigonal planar geometry to one C(13), one C(15), and one S(3) atom. The C(14)-C(15) bond length is 1.35 Å. The C(14)-S(3) bond length is 1.71 Å. In the fifteenth C site, C(15) is bonded in a distorted single-bond geometry to one C(14) and one H(5) atom. The C(15)-H(5) bond length is 0.95 Å. In the sixteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(17) and one H(6) atom. The C(16)-C(17) bond length is 1.35 Å. The C(16)-H(6) bond length is 0.95 Å. In the seventeenth C site, C(17) is bonded in a trigonal planar geometry to one C(16), one C(18), and one S(3) atom. The C(17)-C(18) bond length is 1.47 Å. The C(17)-S(3) bond length is 1.72 Å. In the eighteenth C site, C(18) is bonded in a distorted bent 120 degrees geometry to one C(17), one O(11), and one O(12) atom. The C(18)-O(11) bond length is 1.24 Å. The C(18)-O(12) bond length is 1.30 Å. There are six 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(9) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(10) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(15) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(16) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in an L-shaped geometry to one C(2) and one C(5) atom. In the second S site, S(2) is bonded in an L-shaped geometry to one C(11) and one C(8) atom. In the third S site, S(3) is bonded in an L-shaped geometry to one C(14) and one C(17) atom. There are twelve inequivalent O sites. In the first O site, O(9) is bonded in a bent 150 degrees geometry to one Gd(2) and one C(13) atom. In the second O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Gd(2) and one C(13) atom. In the third O site, O(11) is bonded in a distorted water-like geometry to one Gd(1) and one C(18) atom. In the fourth O site, O(12) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one C(18) atom. In the fifth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one C(1) atom. In the sixth O site, O(2) is bonded in a bent 150 degrees geometry to one Gd(2) and one C(1) atom. In the seventh O site, O(3) is bonded in a bent 120 degrees geometry to one Gd(2) and one C(6) atom. In the eighth O site, O(4) is bonded in a linear geometry to one Gd(2) and one C(6) atom. In the ninth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Gd(2) and one C(7) atom. In the tenth O site, O(6) is bonded in a bent 150 degrees geometry to one Gd(1) and one C(7) atom. In the eleventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one C(12) atom. In the twelfth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one C(12) atom. Linkers: 12 [O]C(=O)c1ccc(C([O])=O)s1. Metal clusters: 8 [Gd]. The MOF has largest included sphere 5.67 A, density 1.72 g/cm3, surface area 2786.42 m2/g, accessible volume 0.31 cm3/g