Cu2C9H4O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form distorted corner-sharing CuO4 trigonal pyramids. The Cu(1)-O(1) bond length is 2.16 Å. The Cu(1)-O(2) bond length is 1.94 Å. The Cu(1)-O(3) bond length is 1.93 Å. The Cu(1)-O(6) bond length is 1.95 Å. In the second Cu site, Cu(2) is bonded to one O(4), one O(5), one O(7), and two equivalent O(6) atoms to form CuO5 trigonal bipyramids that share corners with two equivalent Cu(1)O4 trigonal pyramids and  an edgeedge with one Cu(2)O5 trigonal bipyramid. The Cu(2)-O(4) bond length is 2.19 Å. The Cu(2)-O(5) bond length is 1.96 Å. The Cu(2)-O(7) bond length is 1.97 Å. There is one shorter (1.97 Å) and one longer (2.01 Å) Cu(2)-O(6) bond length. There are nine inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(2), and one O(5) atom. The C(1)-C(3) bond length is 1.50 Å. The C(1)-O(2) bond length is 1.26 Å. The C(1)-O(5) bond length is 1.26 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(6), one C(7), and one C(9) atom. The C(2)-C(6) bond length is 1.39 Å. The C(2)-C(7) bond length is 1.39 Å. The C(2)-C(9) bond length is 1.51 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(6) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-C(6) bond length is 1.40 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(8), and one H(4) atom. The C(4)-C(8) bond length is 1.39 Å. The C(4)-H(4) bond length is 0.95 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(1), and one O(4) atom. The C(5)-C(8) bond length is 1.51 Å. The C(5)-O(1) bond length is 1.26 Å. The C(5)-O(4) bond length is 1.25 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(2), one C(3), and one H(1) atom. The C(6)-H(1) bond length is 0.95 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(2), one C(8), and one H(3) atom. The C(7)-C(8) bond length is 1.39 Å. The C(7)-H(3) bond length is 0.95 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(4), one C(5), and one C(7) atom. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(7) atom. The C(9)-O(3) bond length is 1.25 Å. The C(9)-O(7) bond length is 1.25 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(6) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) atom. The H(2)-O(6) bond length is 1.00 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(4) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Cu(1) and one C(5) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Cu(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one C(9) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(2) and one C(5) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Cu(2) and one C(1) atom. In the sixth O site, O(6) is bonded to one Cu(1), two equivalent Cu(2), and one H(2) atom to form distorted edge-sharing OCu3H tetrahedra. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(2) and one C(9) atom. Linkers: 4 [O]C(=O)c1cc(C([O])=O)cc(C([O])=O)c1. Metal clusters: 2 O[Cu@]12O[C]O[Cu](O[C]O1)O[C]O[Cu@]1(O)O[C]O[Cu](O[C]O2)O[C]O1. RCSR code: rtl. The MOF has largest included sphere 6.38 A, density 1.16 g/cm3, surface area 3110.89 m2/g, accessible volume 0.51 cm3/g