TbCd2C18N5H9O9Cl2C2NH2 crystallizes in the monoclinic Cc space group. The structure consists of four n-methyl methanimine molecules inside a TbCd2C18N5H9O9Cl2 framework. In the TbCd2C18N5H9O9Cl2 framework, Tb(1) is bonded in a 6-coordinate geometry to one H(10), one O(1), one O(2), one O(5), one O(7), and one O(8) atom. The Tb(1)-H(10) bond length is 2.44 Å. The Tb(1)-O(1) bond length is 2.35 Å. The Tb(1)-O(2) bond length is 2.38 Å. The Tb(1)-O(5) bond length is 2.38 Å. The Tb(1)-O(7) bond length is 2.30 Å. The Tb(1)-O(8) bond length is 2.38 Å. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one N(1), one N(6), one O(3), one O(9), and two equivalent Cl(2) atoms to form distorted corner-sharing CdN2Cl2O2 octahedra. The corner-sharing octahedral tilt angles are 27°. The Cd(1)-N(1) bond length is 2.31 Å. The Cd(1)-N(6) bond length is 2.38 Å. The Cd(1)-O(3) bond length is 2.36 Å. The Cd(1)-O(9) bond length is 2.37 Å. There is one shorter (2.54 Å) and one longer (2.61 Å) Cd(1)-Cl(2) bond length. In the second Cd site, Cd(2) is bonded in a distorted trigonal pyramidal geometry to one N(2), one O(4), one O(6), and one Cl(1) atom. The Cd(2)-N(2) bond length is 2.23 Å. The Cd(2)-O(4) bond length is 2.35 Å. The Cd(2)-O(6) bond length is 2.22 Å. The Cd(2)-Cl(1) bond length is 2.46 Å. There are eighteen inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(11), one C(3), and one N(6) atom. The C(1)-C(11) bond length is 1.52 Å. The C(1)-C(3) bond length is 1.38 Å. The C(1)-N(6) bond length is 1.38 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(10), one C(5), and one N(1) atom. The C(2)-C(10) bond length is 1.48 Å. The C(2)-C(5) bond length is 1.39 Å. The C(2)-N(1) bond length is 1.36 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(1), one C(20), and one N(5) atom. The C(3)-C(20) bond length is 1.50 Å. The C(3)-N(5) bond length is 1.37 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(19), one N(3), and one H(1) atom. The C(4)-C(19) bond length is 1.36 Å. The C(4)-N(3) bond length is 1.33 Å. The C(4)-H(1) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(2), one C(9), and one N(2) atom. The C(5)-C(9) bond length is 1.49 Å. The C(5)-N(2) bond length is 1.36 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(14), one N(5), and one N(6) atom. The C(6)-C(14) bond length is 1.48 Å. The C(6)-N(5) bond length is 1.33 Å. The C(6)-N(6) bond length is 1.33 Å. In the seventh C site, C(8) is bonded in a distorted trigonal planar geometry to one C(13), one N(1), and one N(2) atom. The C(8)-C(13) bond length is 1.45 Å. The C(8)-N(1) bond length is 1.34 Å. The C(8)-N(2) bond length is 1.33 Å. In the eighth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(4), and one O(7) atom. The C(9)-O(4) bond length is 1.26 Å. The C(9)-O(7) bond length is 1.27 Å. In the ninth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(2), and one O(3) atom. The C(10)-O(2) bond length is 1.25 Å. The C(10)-O(3) bond length is 1.29 Å. In the tenth C site, C(11) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(9) atom. The C(11)-O(1) bond length is 1.25 Å. The C(11)-O(9) bond length is 1.27 Å. In the eleventh C site, C(12) is bonded in a distorted bent 120 degrees geometry to one N(3) and one H(3) atom. The C(12)-N(3) bond length is 1.35 Å. The C(12)-H(3) bond length is 0.93 Å. In the twelfth C site, C(13) is bonded in a trigonal planar geometry to one C(17), one C(18), and one C(8) atom. The C(13)-C(17) bond length is 1.42 Å. The C(13)-C(18) bond length is 1.39 Å. In the thirteenth C site, C(14) is bonded in a trigonal planar geometry to one C(16), one C(19), and one C(6) atom. The C(14)-C(16) bond length is 1.38 Å. The C(14)-C(19) bond length is 1.42 Å. In the fourteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(14) and one H(5) atom. The C(16)-H(5) bond length is 0.93 Å. In the fifteenth C site, C(17) is bonded in a distorted single-bond geometry to one C(13) and one H(6) atom. The C(17)-H(6) bond length is 0.93 Å. In the sixteenth C site, C(18) is bonded in a distorted single-bond geometry to one C(13) and one H(7) atom. The C(18)-H(7) bond length is 0.93 Å. In the seventeenth C site, C(19) is bonded in a distorted single-bond geometry to one C(14), one C(4), and one H(8) atom. The C(19)-H(8) bond length is 0.93 Å. In the eighteenth C site, C(20) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(6), and one O(8) atom. The C(20)-O(6) bond length is 1.27 Å. The C(20)-O(8) bond length is 1.22 Å. There are five inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal non-coplanar geometry to one Cd(1), one C(2), and one C(8) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Cd(2), one C(5), and one C(8) atom. In the third N site, N(3) is bonded in a bent 120 degrees geometry to one C(12) and one C(4) atom. In the fourth N site, N(5) is bonded in a trigonal planar geometry to one C(3), one C(6), and one H(11) atom. The N(5)-H(11) bond length is 0.86 Å. In the fifth N site, N(6) is bonded in a 3-coordinate geometry to one Cd(1), one C(1), and one C(6) atom. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(4) atom. In the second H site, H(3) is bonded in a single-bond geometry to one C(12) atom. In the third H site, H(5) is bonded in a single-bond geometry to one C(16) atom. In the fourth H site, H(6) is bonded in a single-bond geometry to one C(17) atom. In the fifth H site, H(7) is bonded in a single-bond geometry to one C(18) atom. In the sixth H site, H(8) is bonded in a single-bond geometry to one C(19) atom. In the seventh H site, H(9) is bonded in a single-bond geometry to one O(5) atom. The H(9)-O(5) bond length is 0.94 Å. In the eighth H site, H(10) is bonded in a single-bond geometry to one Tb(1) and one O(5) atom. The H(10)-O(5) bond length is 0.92 Å. In the ninth H site, H(11) is bonded in a single-bond geometry to one N(5) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Tb(1) and one C(11) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Tb(1) and one C(10) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Cd(1) and one C(10) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cd(2) and one C(9) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Tb(1), one H(10), and one H(9) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cd(2) and one C(20) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Tb(1) and one C(9) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Tb(1) and one C(20) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Cd(1) and one C(11) atom. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a single-bond geometry to one Cd(2) atom. In the second Cl site, Cl(2) is bonded in a bent 150 degrees geometry to two equivalent Cd(1) atoms. Linkers: 3 [O]C(=O)[C]1N=C(c2ccncc2)N=C1C([O])=O ,4 [O]C(=O)c1nc(-c2ccncc2)[nH]c1C([O])=O ,1 [O]C(=O)C1=C(C([O])=O)N=C(c2ccncc2)[N]1. Metal clusters: 4 [Tb] ,8 [Cd]. The MOF has largest included sphere 4.04 A, density 2.04 g/cm3, surface area 3164.07 m2/g, accessible volume 0.18 cm3/g