KCrC6H12(NO3)4 crystallizes in the triclinic P-1 space group. K(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(6) atoms. Both K(1)-O(2) bond lengths are 2.68 Å. Both K(1)-O(6) bond lengths are 2.73 Å. Cr(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. Both Cr(1)-O(1) bond lengths are 1.96 Å. Both Cr(1)-O(3) bond lengths are 2.00 Å. Both Cr(1)-O(5) bond lengths are 2.01 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(3) atom. The C(1)-O(2) bond length is 1.23 Å. The C(1)-O(3) bond length is 1.31 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(4) atom. The C(2)-O(1) bond length is 1.30 Å. The C(2)-O(4) bond length is 1.24 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(1), one N(2), and one O(6) atom. The C(3)-N(1) bond length is 1.34 Å. The C(3)-N(2) bond length is 1.41 Å. The C(3)-O(6) bond length is 1.25 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one C(3), one H(5), and one H(6) atom. The N(1)-H(5) bond length is 1.02 Å. The N(1)-H(6) bond length is 1.03 Å. In the second N site, N(2) is bonded in a distorted tetrahedral geometry to one C(3), one H(1), one H(3), and one H(4) atom. The N(2)-H(1) bond length is 1.68 Å. The N(2)-H(3) bond length is 1.02 Å. The N(2)-H(4) bond length is 1.03 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one N(2) and one O(5) atom. The H(1)-O(5) bond length is 1.02 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) and one O(5) atom. The H(2)-O(3) bond length is 1.70 Å. The H(2)-O(5) bond length is 1.00 Å. In the third H site, H(3) is bonded in a single-bond geometry to one N(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(2) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one N(1) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one N(1) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Cr(1), one C(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one C(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one H(1), and one H(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one K(1) and one C(3) atom. Linkers: 2 [O]C(=O)C([O])=O. Metal clusters: 1 [K] ,1 [Cr]. The MOF has largest included sphere 1.86 A, density 1.96 g/cm3, surface area 2791.72 m2/g, accessible volume 0.05 cm3/g