KTbC8(NO4)2 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The K(1)-O(3) bond length is 2.82 Å. Both K(1)-O(1) bond lengths are 2.98 Å. Both K(1)-O(2) bond lengths are 2.63 Å. Tb(1) is bonded in a 7-coordinate geometry to one N(1), one O(3), one O(6), two equivalent O(1), and two equivalent O(2) atoms. The Tb(1)-N(1) bond length is 2.50 Å. The Tb(1)-O(3) bond length is 2.37 Å. The Tb(1)-O(6) bond length is 2.38 Å. Both Tb(1)-O(1) bond lengths are 2.37 Å. Both Tb(1)-O(2) bond lengths are 2.50 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(1)-C(2) bond length is 1.51 Å. The C(1)-O(3) bond length is 1.27 Å. The C(1)-O(4) bond length is 1.23 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one N(1) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-N(1) bond length is 1.33 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one N(2) atom. The C(3)-C(4) bond length is 1.54 Å. The C(3)-N(2) bond length is 1.33 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3) and two equivalent O(1) atoms. Both C(4)-O(1) bond lengths are 1.23 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(6) and two equivalent O(2) atoms. The C(5)-C(6) bond length is 1.48 Å. Both C(5)-O(2) bond lengths are 1.25 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one C(7), and one N(2) atom. The C(6)-C(7) bond length is 1.41 Å. The C(6)-N(2) bond length is 1.33 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(6), one C(8), and one N(1) atom. The C(7)-C(8) bond length is 1.52 Å. The C(7)-N(1) bond length is 1.36 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(5), and one O(6) atom. The C(8)-O(5) bond length is 1.24 Å. The C(8)-O(6) bond length is 1.26 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Tb(1), one C(2), and one C(7) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one C(3) and one C(6) atom. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one Tb(1), and one C(1) atom. In the second O site, O(4) is bonded in a single-bond geometry to one C(1) atom. In the third O site, O(5) is bonded in a single-bond geometry to one C(8) atom. In the fourth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Tb(1) and one C(8) atom. In the fifth O site, O(1) is bonded in a 1-coordinate geometry to one K(1), one Tb(1), and one C(4) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one Tb(1), and one C(5) atom. Linkers: 4 [O]C(=O)c1nc(C([O])=O)c(C([O])=O)nc1C([O])=O. Metal clusters: 4 [K] ,4 [Tb]. The MOF has largest included sphere 4.09 A, density 2.07 g/cm3, surface area 2068.65 m2/g, accessible volume 0.14 cm3/g