CaC10H10(SO4)2 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in an octahedral geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom. The Ca(1)-O(2) bond length is 2.32 Å. The Ca(1)-O(3) bond length is 2.31 Å. The Ca(1)-O(5) bond length is 2.39 Å. The Ca(1)-O(6) bond length is 2.32 Å. The Ca(1)-O(7) bond length is 2.33 Å. The Ca(1)-O(8) bond length is 2.32 Å. There are ten inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(5), and one S(1) atom. The C(1)-C(2) bond length is 1.38 Å. The C(1)-C(5) bond length is 1.43 Å. The C(1)-S(1) bond length is 1.78 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1) and one H(5) atom. The C(2)-H(5) bond length is 1.09 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(4) and one H(6) atom. The C(3)-C(4) bond length is 1.38 Å. The C(3)-H(6) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one H(7) atom. The C(4)-C(5) bond length is 1.42 Å. The C(4)-H(7) bond length is 1.08 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(5) atom. The C(5)-C(5) bond length is 1.44 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(10), one C(7), and one S(2) atom. The C(6)-C(10) bond length is 1.43 Å. The C(6)-C(7) bond length is 1.38 Å. The C(6)-S(2) bond length is 1.78 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(6) and one H(8) atom. The C(7)-H(8) bond length is 1.09 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(9) and one H(9) atom. The C(8)-C(9) bond length is 1.38 Å. The C(8)-H(9) bond length is 1.09 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(10), one C(8), and one H(10) atom. The C(9)-C(10) bond length is 1.42 Å. The C(9)-H(10) bond length is 1.09 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(10), one C(6), and one C(9) atom. The C(10)-C(10) bond length is 1.44 Å. There are ten inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) and one O(7) atom. The H(1)-O(5) bond length is 1.77 Å. The H(1)-O(7) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. The H(2)-O(7) bond length is 0.99 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. The H(3)-O(8) bond length is 0.99 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(8) atom. The H(4)-O(8) bond length is 0.99 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(2) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(3) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(4) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(7) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(8) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(9) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal non-coplanar geometry to one C(1), one O(1), one O(2), and one O(3) atom. The S(1)-O(1) bond length is 1.48 Å. The S(1)-O(2) bond length is 1.47 Å. The S(1)-O(3) bond length is 1.46 Å. In the second S site, S(2) is bonded in a distorted trigonal non-coplanar geometry to one C(6), one O(4), one O(5), and one O(6) atom. The S(2)-O(4) bond length is 1.46 Å. The S(2)-O(5) bond length is 1.49 Å. The S(2)-O(6) bond length is 1.47 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one S(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ca(1) and one S(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Ca(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one S(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one H(1), and one S(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(1) and one S(2) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Ca(1), one H(1), and one H(2) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Ca(1), one H(3), and one H(4) atom. Linkers: 2 [O]S([O])([O])c1cccc2c(S([O])([O])[O])cccc12. Metal clusters: 2 [Ca]. The MOF has largest included sphere 1.87 A, density 1.77 g/cm3, surface area 3938.59 m2/g, accessible volume 0.10 cm3/g