CaCuC12H4(SO4)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 square co-planar geometry to two equivalent O(7) and two equivalent O(8) atoms. Both Ca(1)-O(7) bond lengths are 2.28 Å. Both Ca(1)-O(8) bond lengths are 2.28 Å. In the second Ca site, Ca(2) is bonded in a square co-planar geometry to two equivalent O(4) and two equivalent O(6) atoms. Both Ca(2)-O(4) bond lengths are 2.30 Å. Both Ca(2)-O(6) bond lengths are 2.31 Å. Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Cu(1)-O(1) bond length is 1.95 Å. The Cu(1)-O(2) bond length is 1.96 Å. The Cu(1)-O(3) bond length is 1.97 Å. The Cu(1)-O(4) bond length is 2.54 Å. The Cu(1)-O(5) bond length is 1.96 Å. There are twelve 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(7) atom. The C(1)-C(6) bond length is 1.46 Å. The C(1)-O(1) bond length is 1.24 Å. The C(1)-O(7) bond length is 1.23 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(2), and one O(6) atom. The C(2)-C(5) bond length is 1.51 Å. The C(2)-O(2) bond length is 1.25 Å. The C(2)-O(6) bond length is 1.23 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(4), one C(9), and one S(2) atom. The C(3)-C(4) bond length is 1.47 Å. The C(3)-C(9) bond length is 1.33 Å. The C(3)-S(2) bond length is 1.72 Å. In the fourth C site, C(4) is bonded in a bent 120 degrees geometry to one C(3), one O(4), and one O(5) atom. The C(4)-O(4) bond length is 1.26 Å. The C(4)-O(5) bond length is 1.29 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(11), one C(2), and one S(1) atom. The C(5)-C(11) bond length is 1.35 Å. The C(5)-S(1) bond length is 1.72 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(1), one C(7), and one S(2) atom. The C(6)-C(7) bond length is 1.37 Å. The C(6)-S(2) bond length is 1.76 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(6) and one H(1) atom. The C(7)-H(1) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(10), one O(3), and one O(8) atom. The C(8)-C(10) bond length is 1.51 Å. The C(8)-O(3) bond length is 1.17 Å. The C(8)-O(8) bond length is 1.29 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(3) and one H(2) atom. The C(9)-H(2) bond length is 0.93 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(12), one C(8), and one S(1) atom. The C(10)-C(12) bond length is 1.38 Å. The C(10)-S(1) bond length is 1.71 Å. In the eleventh C site, C(11) is bonded in a distorted single-bond geometry to one C(5) and one H(3) atom. The C(11)-H(3) bond length is 0.93 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(10) and one H(4) atom. The C(12)-H(4) bond length is 0.93 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(9) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(11) 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(10) and one C(5) atom. In the second S site, S(2) is bonded in an L-shaped geometry to one C(3) and one C(6) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(1) and one C(2) atom. In the third O site, O(3) is bonded in a water-like geometry to one Cu(1) and one C(8) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(2), one Cu(1), and one C(4) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one Cu(1) and one C(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(2) and one C(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ca(1) and one C(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ca(1) and one C(8) atom. Linkers: 16 [O]C(=O)c1ccc(C([O])=O)s1. Metal clusters: 8 [Ca] ,8 [Cu]. The MOF has largest included sphere 6.00 A, density 1.16 g/cm3, surface area 3906.51 m2/g, accessible volume 0.43 cm3/g