KNdC4H2O9CH2 crystallizes in the orthorhombic Pbam space group. The structure consists of four 02329_fluka molecules inside a KNdC4H2O9 framework. In the KNdC4H2O9 framework, K(1) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The K(1)-O(6) bond length is 2.75 Å. Both K(1)-O(1) bond lengths are 3.04 Å. Both K(1)-O(2) bond lengths are 2.77 Å. Both K(1)-O(4) bond lengths are 2.75 Å. Nd(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. The Nd(1)-O(3) bond length is 2.57 Å. Both Nd(1)-O(1) bond lengths are 2.50 Å. Both Nd(1)-O(2) bond lengths are 2.49 Å. Both Nd(1)-O(4) bond lengths are 2.49 Å. There is one shorter (2.39 Å) and one longer (2.60 Å) Nd(1)-O(5) bond length. There are three inequivalent C sites. In the first C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. The C(3)-O(3) bond length is 1.26 Å. The C(3)-O(5) bond length is 1.29 Å. In the second C site, C(1) is bonded in a distorted bent 120 degrees geometry to two equivalent O(1) atoms. Both C(1)-O(1) bond lengths are 1.27 Å. In the third C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. The C(2)-O(2) bond length is 1.27 Å. The C(2)-O(4) bond length is 1.27 Å. H(1) is bonded in a single-bond geometry to one O(6) atom. The H(1)-O(6) bond length is 0.98 Å. There are six inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one K(1), one Nd(1), and one C(2) atom. In the second O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Nd(1) and one C(3) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one Nd(1), and one C(1) atom. In the fourth O site, O(6) is bonded in a distorted water-like geometry to one K(1) and two equivalent H(1) atoms. In the fifth O site, O(3) is bonded in a distorted single-bond geometry to one Nd(1) and one C(3) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one Nd(1), and one C(2) atom. Linkers: 6 [O]C(=O)C([O])=O ,2 [O]C(=O)CCC([O])=O. Metal clusters: 4 [K] ,4 [Nd]. The MOF has largest included sphere 3.03 A, density 2.35 g/cm3, surface area 1934.85 m2/g, accessible volume 0.07 cm3/g