Ca2C13H4(SO5)2CH3 crystallizes in the orthorhombic Pca2_1 space group. The structure consists of four 02329_fluka molecules inside a Ca2C13H4(SO5)2 framework. In the Ca2C13H4(SO5)2 framework, there are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(8) atom. The Ca(1)-O(1) bond length is 2.51 Å. The Ca(1)-O(10) bond length is 2.40 Å. The Ca(1)-O(2) bond length is 2.35 Å. The Ca(1)-O(4) bond length is 2.46 Å. The Ca(1)-O(6) bond length is 2.54 Å. The Ca(1)-O(8) bond length is 2.32 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. The Ca(2)-O(1) bond length is 2.39 Å. The Ca(2)-O(2) bond length is 2.54 Å. The Ca(2)-O(3) bond length is 2.41 Å. The Ca(2)-O(5) bond length is 2.33 Å. The Ca(2)-O(6) bond length is 2.42 Å. The Ca(2)-O(7) bond length is 2.54 Å. The Ca(2)-O(8) bond length is 2.65 Å. The Ca(2)-O(9) bond length is 2.29 Å. There are thirteen inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(5) and one H(1) atom. The C(1)-C(5) bond length is 1.37 Å. The C(1)-H(1) bond length is 0.95 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(7) and one H(2) atom. The C(2)-C(7) bond length is 1.37 Å. The C(2)-H(2) bond length is 0.95 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(4), and one O(5) atom. The C(3)-C(6) bond length is 1.49 Å. The C(3)-O(4) bond length is 1.26 Å. The C(3)-O(5) bond length is 1.25 Å. In the fourth C site, C(4) is bonded in a bent 120 degrees geometry to one C(5), one O(2), and one O(7) atom. The C(4)-C(5) bond length is 1.48 Å. The C(4)-O(2) bond length is 1.26 Å. The C(4)-O(7) bond length is 1.25 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(1), one C(4), and one S(2) atom. The C(5)-S(2) bond length is 1.72 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(12), one C(3), and one S(1) atom. The C(6)-C(12) bond length is 1.37 Å. The C(6)-S(1) bond length is 1.72 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(2), one C(9), and one S(2) atom. The C(7)-C(9) bond length is 1.49 Å. The C(7)-S(2) bond length is 1.72 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(10), one C(11), and one S(1) atom. The C(8)-C(10) bond length is 1.37 Å. The C(8)-C(11) bond length is 1.48 Å. The C(8)-S(1) bond length is 1.72 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(10), and one O(9) atom. The C(9)-O(10) bond length is 1.26 Å. The C(9)-O(9) bond length is 1.25 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(8) and one H(3) atom. The C(10)-H(3) bond length is 0.95 Å. In the eleventh C site, C(11) is bonded in a bent 120 degrees geometry to one C(8), one O(3), and one O(8) atom. The C(11)-O(3) bond length is 1.25 Å. The C(11)-O(8) bond length is 1.27 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(6) and one H(4) atom. The C(12)-H(4) bond length is 0.95 Å. In the thirteenth C site, C(13) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(6) atom. The C(13)-O(1) bond length is 1.27 Å. The C(13)-O(6) bond length is 1.27 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(10) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(12) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded in an L-shaped geometry to one C(6) and one C(8) atom. In the second S site, S(2) is bonded in an L-shaped geometry to one C(5) and one C(7) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one C(13) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one Ca(2), and one C(4) atom. In the third O site, O(3) is bonded in a water-like geometry to one Ca(2) and one C(11) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one Ca(1) and one C(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ca(2) and one C(3) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), and one C(13) atom. In the seventh O site, O(7) is bonded in an L-shaped geometry to one Ca(2) and one C(4) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one C(11) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Ca(2) and one C(9) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Ca(1) and one C(9) atom. Linkers: 8 [O]C(=O)c1ccc(C([O])=O)s1. Metal clusters: 8 [Ca]. The MOF has largest included sphere 7.95 A, density 0.98 g/cm3, surface area 3877.01 m2/g, accessible volume 0.55 cm3/g