MnC7NH5O5 crystallizes in the trigonal R-3 space group. Mn(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 67°. The Mn(1)-O(1) bond length is 2.14 Å. The Mn(1)-O(3) bond length is 2.13 Å. The Mn(1)-O(4) bond length is 2.11 Å. The Mn(1)-O(5) bond length is 2.21 Å. There is one shorter (2.16 Å) and one longer (2.20 Å) Mn(1)-O(2) bond length. There are seven inequivalent C sites. In the first C site, C(5) is bonded in a distorted single-bond geometry to one C(3), one C(6), and one H(3) atom. The C(5)-C(3) bond length is 1.40 Å. The C(5)-C(6) bond length is 1.38 Å. The C(5)-H(3) bond length is 1.09 Å. In the second C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one N(1), and one H(4) atom. The C(6)-N(1) bond length is 1.37 Å. The C(6)-H(4) bond length is 1.09 Å. In the third C site, C(7) is bonded in a trigonal planar geometry to one H(5), one O(2), and one O(5) atom. The C(7)-H(5) bond length is 1.11 Å. The C(7)-O(2) bond length is 1.29 Å. The C(7)-O(5) bond length is 1.26 Å. In the fourth C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(1), and one O(4) atom. The C(1)-C(3) bond length is 1.50 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(4) bond length is 1.27 Å. In the fifth C site, C(2) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one H(1) atom. The C(2)-C(4) bond length is 1.38 Å. The C(2)-N(1) bond length is 1.37 Å. The C(2)-H(1) bond length is 1.09 Å. In the sixth C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(5) atom. The C(3)-C(4) bond length is 1.40 Å. In the seventh C site, C(4) is bonded in a distorted single-bond geometry to one C(2), one C(3), and one H(2) atom. The C(4)-H(2) bond length is 1.09 Å. N(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one O(3) atom. The N(1)-O(3) bond length is 1.32 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(7) atom. There are five inequivalent O sites. In the first O site, O(2) is bonded in a trigonal planar geometry to two equivalent Mn(1) and one C(7) atom. In the second O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one N(1) atom. In the third O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(1) atom. In the fourth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one C(7) atom. In the fifth O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(1) atom. Linkers: 6 [O]C(=O)c1cc[n+]([O-])cc1. Metal clusters: 1 [O][Mn]123O[C]O[Mn]4([O])(O[C]O[Mn]5([O])(O[C]O[Mn]6([O])(O[C]O[Mn]7([O])(O[C]O[Mn]([O])(O[C]O1)(O[CH]O2)O[CH]O7)O[CH]O6)O[CH]O5)O[CH]O4)O[CH]O3. RCSR code: pcu. The MOF has largest included sphere 2.09 A, density 1.90 g/cm3, surface area 3431.85 m2/g, accessible volume 0.09 cm3/g