Zn3C20H18(N4O)4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a trigonal non-coplanar geometry to one N(1), one N(5), and one O(1) atom. The Zn(1)-N(1) bond length is 2.00 Å. The Zn(1)-N(5) bond length is 2.00 Å. The Zn(1)-O(1) bond length is 1.95 Å. In the second Zn site, Zn(2) is bonded in a tetrahedral geometry to two equivalent N(4) and two equivalent N(8) atoms. Both Zn(2)-N(4) bond lengths are 1.98 Å. Both Zn(2)-N(8) bond lengths are 1.99 Å. There are ten inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one N(1), and one N(4) atom. The C(1)-C(2) bond length is 1.49 Å. The C(1)-N(1) bond length is 1.33 Å. The C(1)-N(4) bond length is 1.34 Å. In the second C site, C(2) is bonded in a trigonal non-coplanar geometry to one C(1); one H(1); and two equivalent H(2,3) atoms. The C(2)-H(1) bond length is 0.96 Å. Both C(2)-H(2,3) bond lengths are 0.96 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(4), one N(5), and one N(8) atom. The C(3)-C(4) bond length is 1.48 Å. The C(3)-N(5) bond length is 1.33 Å. The C(3)-N(8) bond length is 1.33 Å. In the fourth C site, C(4) is bonded in a trigonal non-coplanar geometry to one C(3); one H(6); and two equivalent H(4,5) atoms. The C(4)-H(6) bond length is 0.96 Å. Both C(4)-H(4,5) bond lengths are 0.96 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(1), and one O(2) atom. The C(5)-C(6) bond length is 1.50 Å. The C(5)-O(1) bond length is 1.27 Å. The C(5)-O(2) bond length is 1.24 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(10), one C(5), and one C(7) atom. The C(6)-C(10) bond length is 1.37 Å. The C(6)-C(7) bond length is 1.41 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(6) and one H(7) atom. The C(7)-H(7) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a single-bond geometry to one C(9) and one H(8) atom. The C(8)-C(9) bond length is 1.41 Å. The C(8)-H(8) bond length is 0.93 Å. In the ninth C site, C(9) is bonded in a trigonal planar geometry to one C(10), one C(8), and one C(9) atom. The C(9)-C(10) bond length is 1.42 Å. The C(9)-C(9) bond length is 1.40 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(6), one C(9), and one H(9) atom. The C(10)-H(9) bond length is 0.93 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Zn(1), one C(1), and one N(2) atom. The N(1)-N(2) bond length is 1.37 Å. In the second N site, N(2) is bonded in a water-like geometry to one N(1) and one N(3) atom. The N(2)-N(3) bond length is 1.28 Å. In the third N site, N(3) is bonded in a water-like geometry to one N(2) and one N(4) atom. The N(3)-N(4) bond length is 1.36 Å. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one Zn(2), one C(1), and one N(3) atom. In the fifth N site, N(5) is bonded in a 2-coordinate geometry to one Zn(1), one C(3), and one N(6) atom. The N(5)-N(6) bond length is 1.36 Å. In the sixth N site, N(6) is bonded in a water-like geometry to one N(5) and one N(7) atom. The N(6)-N(7) bond length is 1.29 Å. In the seventh N site, N(7) is bonded in a water-like geometry to one N(6) and one N(8) atom. The N(7)-N(8) bond length is 1.36 Å. In the eighth N site, N(8) is bonded in a distorted trigonal planar geometry to one Zn(2), one C(3), and one N(7) atom. There are seven 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(2,3) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(4,5) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(6) is bonded in a single-bond geometry to one C(4) atom. In the fifth H site, H(7) is bonded in a single-bond geometry to one C(7) atom. In the sixth H site, H(8) is bonded in a single-bond geometry to one C(8) atom. In the seventh H site, H(9) is bonded in a single-bond geometry to one C(10) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Zn(1) and one C(5) atom. In the second O site, O(2) is bonded in a single-bond geometry to one C(5) atom. Linkers: 16 CC1=NN=N[N]1 ,4 [O]C(=O)c1ccc2cc(C([O])=O)ccc2c1. Metal clusters: 8 O=[C]O[Zn] ,4 [Zn]. The MOF has largest included sphere 5.73 A, density 1.21 g/cm3, surface area 4519.30 m2/g, accessible volume 0.40 cm3/g