K3C5H4O6CHO crystallizes in the orthorhombic Pna2_1 space group. The structure consists of four methanol molecules inside a K3C5H4O6 framework. In the K3C5H4O6 framework, there are three inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one H(4), one O(1), one O(3), one O(4), one O(5), and one O(6) atom. The K(1)-H(4) bond length is 2.63 Å. The K(1)-O(1) bond length is 2.67 Å. The K(1)-O(3) bond length is 2.70 Å. The K(1)-O(4) bond length is 2.69 Å. The K(1)-O(5) bond length is 2.98 Å. The K(1)-O(6) bond length is 2.67 Å. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. The K(2)-O(1) bond length is 2.82 Å. The K(2)-O(4) bond length is 2.83 Å. There is one shorter (2.80 Å) and one longer (3.05 Å) K(2)-O(2) bond length. There is one shorter (2.80 Å) and one longer (2.96 Å) K(2)-O(3) bond length. There is one shorter (2.97 Å) and one longer (3.03 Å) K(2)-O(5) bond length. In the third K site, K(3) is bonded in a 6-coordinate geometry to one H(1), one O(1), one O(2), one O(4), one O(5), and one O(6) atom. The K(3)-H(1) bond length is 2.62 Å. The K(3)-O(1) bond length is 2.72 Å. The K(3)-O(2) bond length is 2.70 Å. The K(3)-O(4) bond length is 2.68 Å. The K(3)-O(5) bond length is 2.93 Å. The K(3)-O(6) bond length is 2.68 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(2) atom. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.28 Å. In the second C site, C(2) is bonded in a distorted water-like geometry to one H(1) and one H(2) atom. The C(2)-H(1) bond length is 1.10 Å. The C(2)-H(2) bond length is 1.10 Å. In the third C site, C(4) is bonded in a distorted water-like geometry to one H(3) and one H(4) atom. The C(4)-H(3) bond length is 1.10 Å. The C(4)-H(4) bond length is 1.10 Å. In the fourth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(4) atom. The C(5)-O(3) bond length is 1.28 Å. The C(5)-O(4) bond length is 1.27 Å. In the fifth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(6) atom. The C(6)-O(5) bond length is 1.27 Å. The C(6)-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 K(3) and one C(2) 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(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one K(1) and one C(4) atom. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted single-bond geometry to one K(1), two equivalent K(2), and one C(5) atom. In the second O site, O(4) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), and one C(5) atom. In the third O site, O(5) is bonded in a single-bond geometry to one K(1), one K(3), two equivalent K(2), and one C(6) atom. In the fourth O site, O(6) is bonded in a distorted single-bond geometry to one K(1), one K(3), and one C(6) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), and one C(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one K(3), two equivalent K(2), and one C(1) atom. Linkers: 4 [O]C(=O)CC(O)(CC([O])=O)C([O])=O. Metal clusters: 12 [K]. The MOF has largest included sphere 1.08 A, density 2.05 g/cm3, surface area 0.00 m2/g, accessible volume 0.00 cm3/g