Ca3C22H18(SO7)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms. The Ca(1)-O(1) bond length is 2.48 Å. The Ca(1)-O(3) bond length is 2.59 Å. The Ca(1)-O(4) bond length is 2.36 Å. The Ca(1)-O(5) bond length is 2.43 Å. The Ca(1)-O(6) bond length is 2.59 Å. There is one shorter (2.36 Å) and one longer (2.60 Å) Ca(1)-O(2) bond length. In the second Ca site, Ca(2) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(7) atoms. Both Ca(2)-O(1) bond lengths are 2.31 Å. Both Ca(2)-O(3) bond lengths are 2.41 Å. Both Ca(2)-O(7) bond lengths are 2.29 Å. There are eleven inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(1), and one O(6) atom. The C(1)-C(6) bond length is 1.51 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(6) bond length is 1.26 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(5), one C(6), and one H(1) atom. The C(2)-C(5) bond length is 1.38 Å. The C(2)-C(6) bond length is 1.39 Å. The C(2)-H(1) bond length is 0.93 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(4), and one O(7) atom. The C(3)-C(5) bond length is 1.51 Å. The C(3)-O(4) bond length is 1.25 Å. The C(3)-O(7) bond length is 1.27 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(10), one C(7), and one C(9) atom. The C(4)-C(10) bond length is 1.51 Å. The C(4)-C(7) bond length is 1.41 Å. The C(4)-C(9) bond length is 1.39 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(7) atom. The C(5)-C(7) bond length is 1.40 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(1), one C(2), and one C(9) atom. The C(6)-C(9) bond length is 1.40 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(4), one C(5), and one H(2) atom. The C(7)-H(2) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a trigonal non-coplanar geometry to one H(3); two equivalent H(4,5); and one S(1) atom. The C(8)-H(3) bond length is 0.96 Å. Both C(8)-H(4,5) bond lengths are 0.96 Å. The C(8)-S(1) bond length is 1.78 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(4), one C(6), and one H(6) atom. The C(9)-H(6) bond length is 0.93 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(2), and one O(5) atom. The C(10)-O(2) bond length is 1.27 Å. The C(10)-O(5) bond length is 1.25 Å. In the eleventh C site, C(11) is bonded in a trigonal non-coplanar geometry to one H(7), one H(8), one H(9), and one S(1) atom. The C(11)-H(7) bond length is 0.96 Å. The C(11)-H(8) bond length is 0.96 Å. The C(11)-H(9) bond length is 0.96 Å. The C(11)-S(1) bond length is 1.76 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(7) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(8) atom. In the fourth H site, H(4,5) is bonded in a single-bond geometry to one C(8) atom. In the fifth H site, H(6) is bonded in a single-bond geometry to one C(9) atom. In the sixth H site, H(7) is bonded in a single-bond geometry to one C(11) atom. In the seventh H site, H(8) is bonded in a single-bond geometry to one C(11) atom. In the eighth H site, H(9) is bonded in a single-bond geometry to one C(11) atom. S(1) is bonded in a distorted trigonal non-coplanar geometry to one C(11), one C(8), and one O(3) atom. The S(1)-O(3) bond length is 1.53 Å. There are seven 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(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one C(10) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one S(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(1) and one C(3) atom. In the fifth O site, O(5) is bonded in a distorted L-shaped geometry to one Ca(1) and one C(10) atom. In the sixth O site, O(6) is bonded in a distorted L-shaped geometry to one Ca(1) and one C(1) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Ca(2) and one C(3) atom. Linkers: 4 [O]C(=O)c1cc(C([O])=O)cc(C([O])=O)c1. Metal clusters: 6 [Ca]. The MOF has largest included sphere 6.29 A, density 1.17 g/cm3, surface area 4184.63 m2/g, accessible volume 0.41 cm3/g