Mg3C30N3H18O25(C4NH2)3 is Indium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is zero-dimensional and consists of two C4NH2 clusters and two Mg3C30N3H18O25 clusters. In each C4NH2 cluster, there are three inequivalent C sites. In the first C site, C(2) is bonded in a trigonal planar geometry to one C(3) and two equivalent C(7) atoms. The C(2)-C(3) bond length is 1.52 Å. Both C(2)-C(7) bond lengths are 1.35 Å. In the second C site, C(3) is bonded in a trigonal planar geometry to one C(2) and two equivalent N(2) atoms. Both C(3)-N(2) bond lengths are 1.35 Å. In the third C site, C(7) is bonded in a distorted single-bond geometry to one C(2) and one H(3) atom. The C(7)-H(3) bond length is 0.93 Å. N(2) is bonded in a bent 120 degrees geometry to two equivalent C(3) atoms. H(3) is bonded in a single-bond geometry to one C(7) atom. In each Mg3C30N3H18O25 cluster, Mg(1) is bonded to one N(1), one O(3), and four equivalent O(1) atoms to form corner-sharing MgNO5 octahedra. The corner-sharing octahedral tilt angles are 60°. The Mg(1)-N(1) bond length is 2.14 Å. The Mg(1)-O(3) bond length is 1.97 Å. All Mg(1)-O(1) bond lengths are 2.02 Å. There are four inequivalent C sites. In the first C site, C(6) is bonded in a distorted bent 120 degrees geometry to one N(1) and one H(2) atom. The C(6)-N(1) bond length is 1.34 Å. The C(6)-H(2) bond length is 0.93 Å. In the second C site, C(1) is bonded in a distorted single-bond geometry to one C(5) and one O(2) atom. The C(1)-C(5) bond length is 1.38 Å. The C(1)-O(2) bond length is 1.36 Å. In the third C site, C(4) is bonded in a bent 120 degrees geometry to one C(5) and two equivalent O(1) atoms. The C(4)-C(5) bond length is 1.50 Å. Both C(4)-O(1) bond lengths are 1.26 Å. In the fourth C site, C(5) is bonded in a trigonal planar geometry to one C(4) and two equivalent C(1) atoms. N(1) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent C(6) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(2) atom. The H(1)-O(2) bond length is 0.82 Å. In the second H site, H(2) is bonded in a single-bond geometry to 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 Mg(1) atoms. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one C(4) atom. In the third O site, O(2) is bonded in a distorted water-like geometry to one C(1) and one H(1) atom. Linkers: 2 n1ccc(cc1)C1=NC(=[N]=C([N]1)c1ccncc1)c1ccncc1 ,6 [O]C(=O)c1c(O)c(O)c(C([O])=O)c(O)c1O. Metal clusters: 1 O=[C]O[Mg]O[Mg]O[C]O[Mg].[O][C]=O.[O][C]=O.[O][C]=O.[O][C]=O ,1 O=[C]O[Mg].O=[C]O[Mg]O[Mg]O[C]=O.[O][C]=O.[O][C]=O.[O][C]=O. RCSR code: acs. The MOF has largest included sphere 8.84 A, density 0.98 g/cm3, surface area 3856.14 m2/g, accessible volume 0.58 cm3/g