Cr3C42O13 crystallizes in the hexagonal P-62c space group. Cr(1) is bonded in a single-bond geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Cr(1)-O(3) bond length is 2.01 Å. Both Cr(1)-O(1) bond lengths are 1.98 Å. Both Cr(1)-O(2) bond lengths are 2.08 Å. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.47 Å. The C(1)-O(1) bond length is 1.19 Å. The C(1)-O(2) bond length is 1.21 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(7) atom. The C(2)-C(3) bond length is 1.47 Å. The C(2)-C(7) bond length is 1.44 Å. In the third C site, C(3) is bonded in a bent 120 degrees geometry to one C(2) and one C(4) atom. The C(3)-C(4) bond length is 1.45 Å. In the fourth C site, C(4) is bonded in a bent 120 degrees geometry to one C(3) and one C(5) atom. The C(4)-C(5) bond length is 1.40 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(5), and one C(6) atom. The C(5)-C(5) bond length is 1.47 Å. The C(5)-C(6) bond length is 1.32 Å. In the sixth C site, C(6) is bonded in a single-bond geometry to one C(5) and one C(7) atom. The C(6)-C(7) bond length is 1.44 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(2) and one C(6) atom. There are three inequivalent O sites. In the first O site, O(3) is bonded in a trigonal planar geometry to three equivalent Cr(1) atoms. In the second O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one C(1) atom. In the third O site, O(2) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(1) atom. Linkers: 6 [O]C(=O)c1[c][c]c(-c2[c][c]c(C([O])=O)[c][c]2)[c][c]1. Metal clusters: 2 [C]1O[Cr]23O[C]O[Cr]45(O1)O[C]O[Cr](O[C]O2)(O[C]O3)(O[C]O4)O5. RCSR code: acs. The MOF has largest included sphere 6.88 A, density 0.83 g/cm3, surface area 4116.81 m2/g, accessible volume 0.76 cm3/g