ZnH4(C3N5)2 crystallizes in the orthorhombic Pbca space group. Zn(1) is bonded in an octahedral geometry to one N(1), one N(2), one N(5), one N(7), one N(8), and one N(9) atom. The Zn(1)-N(1) bond length is 2.09 Å. The Zn(1)-N(2) bond length is 2.13 Å. The Zn(1)-N(5) bond length is 2.19 Å. The Zn(1)-N(7) bond length is 2.30 Å. The Zn(1)-N(8) bond length is 2.33 Å. The Zn(1)-N(9) bond length is 2.10 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(3) atom. The C(1)-N(1) bond length is 1.35 Å. The C(1)-N(2) bond length is 1.34 Å. The C(1)-H(3) bond length is 1.09 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(3), one N(1), and one N(3) atom. The C(2)-C(3) bond length is 1.45 Å. The C(2)-N(1) bond length is 1.37 Å. The C(2)-N(3) bond length is 1.34 Å. In the third C site, C(3) is bonded in a distorted water-like geometry to one C(2), one N(4), and one N(6) atom. The C(3)-N(4) bond length is 1.33 Å. The C(3)-N(6) bond length is 1.38 Å. In the fourth C site, C(4) is bonded in a distorted water-like geometry to one C(5), one N(5), and one N(6) atom. The C(4)-C(5) bond length is 1.44 Å. The C(4)-N(5) bond length is 1.33 Å. The C(4)-N(6) bond length is 1.36 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one N(10), and one N(8) atom. The C(5)-N(10) bond length is 1.34 Å. The C(5)-N(8) bond length is 1.36 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(8), one N(9), and one H(4) atom. The C(6)-N(8) bond length is 1.34 Å. The C(6)-N(9) bond length is 1.35 Å. The C(6)-H(4) bond length is 1.09 Å. There are ten inequivalent N sites. In the first N site, N(6) is bonded in a distorted trigonal planar geometry to one C(3), one C(4), and one N(7) atom. The N(6)-N(7) bond length is 1.40 Å. In the second N site, N(7) is bonded in a distorted water-like geometry to one Zn(1), one N(6), one H(1), and one H(2) atom. The N(7)-H(1) bond length is 1.04 Å. The N(7)-H(2) bond length is 1.03 Å. In the third N site, N(8) is bonded in a 3-coordinate geometry to one Zn(1), one C(5), and one C(6) atom. In the fourth N site, N(9) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(6), and one N(10) atom. The N(9)-N(10) bond length is 1.36 Å. In the fifth N site, N(10) is bonded in a distorted water-like geometry to one C(5) and one N(9) atom. In the sixth N site, N(1) is bonded in a trigonal planar geometry to one Zn(1), one C(1), and one C(2) atom. In the seventh N site, N(2) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(1), and one N(3) atom. The N(2)-N(3) bond length is 1.36 Å. In the eighth N site, N(3) is bonded in a water-like geometry to one C(2) and one N(2) atom. In the ninth N site, N(4) is bonded in a water-like geometry to one C(3) and one N(5) atom. The N(4)-N(5) bond length is 1.37 Å. In the tenth N site, N(5) is bonded in a 3-coordinate geometry to one Zn(1), one C(4), and one N(4) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(7) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(1) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. Linkers: 5 Nn1c(nnc1C1=[N]=CN=N1)C1=[N]=CN=N1 ,1 Nn1c(nnc1C1=[N]=CN=N1)C1=N[N]C=N1 ,1 Nn1c(nnc1C1=[N]=CN=N1)C1=NC=N[N]1 ,1 Nn1c(C2=NC=N[N]2)nnc1C1=N[N]C=N1. Metal clusters: 8 [Zn]. The MOF has largest included sphere 3.70 A, density 1.61 g/cm3, surface area 3455.59 m2/g, accessible volume 0.20 cm3/g