MnC3N4H4O3 crystallizes in the monoclinic P2_1/c space group. Mn(1) is bonded in an octahedral geometry to one N(1), one N(2), one N(3), one O(1), one O(2), and one O(3) atom. The Mn(1)-N(1) bond length is 2.20 Å. The Mn(1)-N(2) bond length is 2.13 Å. The Mn(1)-N(3) bond length is 2.20 Å. The Mn(1)-O(1) bond length is 2.24 Å. The Mn(1)-O(2) bond length is 2.37 Å. The Mn(1)-O(3) bond length is 2.23 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(2), one N(3), and one N(4) atom. The C(1)-N(2) bond length is 1.37 Å. The C(1)-N(3) bond length is 1.36 Å. The C(1)-N(4) bond length is 1.35 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one N(1) and one N(3) atom. The C(2)-N(1) bond length is 1.33 Å. The C(2)-N(3) bond length is 1.36 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(2) atom. The C(3)-O(1) bond length is 1.27 Å. The C(3)-O(2) bond length is 1.28 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Mn(1), one C(2), and one N(2) atom. The N(1)-N(2) bond length is 1.38 Å. In the second N site, N(2) is bonded in a 3-coordinate geometry to one Mn(1), one C(1), and one N(1) atom. In the third N site, N(3) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1), one C(1), and one C(2) atom. In the fourth N site, N(4) is bonded in a distorted trigonal non-coplanar geometry to one C(1), one H(1), and one H(2) atom. The N(4)-H(1) bond length is 1.03 Å. The N(4)-H(2) bond length is 1.02 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(4) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one O(2) and one O(3) atom. The H(3)-O(2) bond length is 1.65 Å. The H(3)-O(3) bond length is 1.01 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(3) atom. The H(4)-O(3) bond length is 0.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(3) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1), one C(3), and one H(3) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Mn(1), one H(3), and one H(4) atom. Linkers: 2 NC1=NN=C(C([O])=O)[N]1 ,2 NC1=NC(C([O])=O)=N[N]1. Metal clusters: 4 [Mn]. The MOF has largest included sphere 2.46 A, density 1.95 g/cm3, surface area 3174.56 m2/g, accessible volume 0.15 cm3/g