KHoC8(NO4)2 crystallizes in the orthorhombic Pnma space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(14), one O(2), and one O(9) atom. The K(1)-O(1) bond length is 3.07 Å. The K(1)-O(12) bond length is 2.65 Å. The K(1)-O(14) bond length is 2.93 Å. The K(1)-O(2) bond length is 2.63 Å. The K(1)-O(9) bond length is 3.14 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(13), one O(15), one O(19), and one O(20) atom. The K(2)-O(10) bond length is 2.91 Å. The K(2)-O(11) bond length is 2.73 Å. The K(2)-O(13) bond length is 3.12 Å. The K(2)-O(15) bond length is 2.61 Å. The K(2)-O(19) bond length is 3.18 Å. The K(2)-O(20) bond length is 2.87 Å. In the third K site, K(3) is bonded in a distorted hexagonal planar geometry to one O(18), one O(4), two equivalent O(3), and two equivalent O(7) atoms. The K(3)-O(18) bond length is 3.07 Å. The K(3)-O(4) bond length is 2.86 Å. Both K(3)-O(3) bond lengths are 2.68 Å. Both K(3)-O(7) bond lengths are 3.01 Å. There are three inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 7-coordinate geometry to one N(3), one O(2), one O(20), one O(3), one O(6), one O(7), and one O(9) atom. The Ho(1)-N(3) bond length is 2.48 Å. The Ho(1)-O(2) bond length is 2.58 Å. The Ho(1)-O(20) bond length is 2.35 Å. The Ho(1)-O(3) bond length is 2.43 Å. The Ho(1)-O(6) bond length is 2.37 Å. The Ho(1)-O(7) bond length is 2.38 Å. The Ho(1)-O(9) bond length is 2.35 Å. In the second Ho site, Ho(2) is bonded in a 7-coordinate geometry to one N(2), one O(1), one O(10), one O(11), one O(12), one O(14), and one O(21) atom. The Ho(2)-N(2) bond length is 2.50 Å. The Ho(2)-O(1) bond length is 2.34 Å. The Ho(2)-O(10) bond length is 2.37 Å. The Ho(2)-O(11) bond length is 2.48 Å. The Ho(2)-O(12) bond length is 2.57 Å. The Ho(2)-O(14) bond length is 2.37 Å. The Ho(2)-O(21) bond length is 2.40 Å. In the third Ho site, Ho(3) is bonded in a 7-coordinate geometry to one N(6), one O(16), one O(4), two equivalent O(13), and two equivalent O(15) atoms. The Ho(3)-N(6) bond length is 2.47 Å. The Ho(3)-O(16) bond length is 2.38 Å. The Ho(3)-O(4) bond length is 2.36 Å. Both Ho(3)-O(13) bond lengths are 2.38 Å. Both Ho(3)-O(15) bond lengths are 2.50 Å. There are twenty-four inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(24), one C(5), and one N(6) atom. The C(1)-C(24) bond length is 1.53 Å. The C(1)-C(5) bond length is 1.36 Å. The C(1)-N(6) bond length is 1.36 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(15), one C(16), and one N(2) atom. The C(2)-C(15) bond length is 1.38 Å. The C(2)-C(16) bond length is 1.52 Å. The C(2)-N(2) bond length is 1.34 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(13), one C(8), and one N(3) atom. The C(3)-C(13) bond length is 1.52 Å. The C(3)-C(8) bond length is 1.39 Å. The C(3)-N(3) bond length is 1.34 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(10), one C(9), and one N(4) atom. The C(4)-C(10) bond length is 1.51 Å. The C(4)-C(9) bond length is 1.40 Å. The C(4)-N(4) bond length is 1.33 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(1), one C(18), and one N(4) atom. The C(5)-C(18) bond length is 1.52 Å. The C(5)-N(4) bond length is 1.36 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(14), one O(2), and one O(3) atom. The C(6)-C(14) bond length is 1.53 Å. The C(6)-O(2) bond length is 1.24 Å. The C(6)-O(3) bond length is 1.25 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(22), one C(23), and one N(5) atom. The C(7)-C(22) bond length is 1.39 Å. The C(7)-C(23) bond length is 1.53 Å. The C(7)-N(5) bond length is 1.35 Å. In the eighth C site, C(8) is bonded in a distorted trigonal planar geometry to one C(11), one C(3), and one N(1) atom. The C(8)-C(11) bond length is 1.53 Å. The C(8)-N(1) bond length is 1.35 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(17), one C(4), and one N(6) atom. The C(9)-C(17) bond length is 1.53 Å. The C(9)-N(6) bond length is 1.33 Å. In the tenth C site, C(10) is bonded in a distorted trigonal planar geometry to one C(4) and two equivalent O(7) atoms. Both C(10)-O(7) bond lengths are 1.26 Å. In the eleventh C site, C(11) is bonded in a distorted trigonal planar geometry to one C(8), one O(10), and one O(13) atom. The C(11)-O(10) bond length is 1.25 Å. The C(11)-O(13) bond length is 1.24 Å. In the twelfth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(22), one O(14), and one O(5) atom. The C(12)-C(22) bond length is 1.52 Å. The C(12)-O(14) bond length is 1.27 Å. The C(12)-O(5) bond length is 1.23 Å. In the thirteenth C site, C(13) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(19), and one O(20) atom. The C(13)-O(19) bond length is 1.23 Å. The C(13)-O(20) bond length is 1.27 Å. In the fourteenth C site, C(14) is bonded in a distorted trigonal planar geometry to one C(19), one C(6), and one N(1) atom. The C(14)-C(19) bond length is 1.39 Å. The C(14)-N(1) bond length is 1.35 Å. In the fifteenth C site, C(15) is bonded in a distorted trigonal planar geometry to one C(2), one C(20), and one N(5) atom. The C(15)-C(20) bond length is 1.51 Å. The C(15)-N(5) bond length is 1.34 Å. In the sixteenth C site, C(16) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(17), and one O(21) atom. The C(16)-O(17) bond length is 1.23 Å. The C(16)-O(21) bond length is 1.26 Å. In the seventeenth C site, C(17) is bonded in a distorted bent 120 degrees geometry to one C(9), one O(18), and one O(4) atom. The C(17)-O(18) bond length is 1.23 Å. The C(17)-O(4) bond length is 1.27 Å. In the eighteenth C site, C(18) is bonded in a distorted bent 120 degrees geometry to one C(5) and two equivalent O(15) atoms. Both C(18)-O(15) bond lengths are 1.24 Å. In the nineteenth C site, C(19) is bonded in a distorted single-bond geometry to one C(14) and one N(3) atom. The C(19)-N(3) bond length is 1.32 Å. In the twentieth C site, C(20) is bonded in a distorted bent 120 degrees geometry to one C(15), one O(11), and one O(12) atom. The C(20)-O(11) bond length is 1.26 Å. The C(20)-O(12) bond length is 1.24 Å. In the twenty-first C site, C(21) is bonded in a distorted bent 120 degrees geometry to one O(6) and one O(8) atom. The C(21)-O(6) bond length is 1.27 Å. The C(21)-O(8) bond length is 1.23 Å. In the twenty-second C site, C(22) is bonded in a distorted trigonal planar geometry to one C(12), one C(7), and one N(2) atom. The C(22)-N(2) bond length is 1.34 Å. In the twenty-third C site, C(23) is bonded in a distorted trigonal planar geometry to one C(7), one O(1), and one O(9) atom. The C(23)-O(1) bond length is 1.25 Å. The C(23)-O(9) bond length is 1.24 Å. In the twenty-fourth C site, C(24) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(16), and one O(22) atom. The C(24)-O(16) bond length is 1.26 Å. The C(24)-O(22) bond length is 1.25 Å. There are six inequivalent N sites. In the first N site, N(1) is bonded in a bent 120 degrees geometry to one C(14) and one C(8) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Ho(2), one C(2), and one C(22) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Ho(1), one C(19), and one C(3) atom. In the fourth N site, N(4) is bonded in a bent 120 degrees geometry to one C(4) and one C(5) atom. In the fifth N site, N(5) is bonded in a bent 120 degrees geometry to one C(15) and one C(7) atom. In the sixth N site, N(6) is bonded in a distorted trigonal planar geometry to one Ho(3), one C(1), and one C(9) atom. There are twenty-two inequivalent O sites. In the first O site, O(12) is bonded in a distorted single-bond geometry to one K(1), one Ho(2), and one C(20) atom. In the second O site, O(13) is bonded in a 1-coordinate geometry to one K(2), one Ho(3), and one C(11) atom. In the third O site, O(14) is bonded in a distorted single-bond geometry to one K(1), one Ho(2), and one C(12) atom. In the fourth O site, O(15) is bonded in a distorted single-bond geometry to one K(2), one Ho(3), and one C(18) atom. In the fifth O site, O(16) is bonded in a bent 120 degrees geometry to one Ho(3) and one C(24) atom. In the sixth O site, O(17) is bonded in a single-bond geometry to one C(16) atom. In the seventh O site, O(18) is bonded in a single-bond geometry to one K(3) and one C(17) atom. In the eighth O site, O(19) is bonded in a single-bond geometry to one K(2) and one C(13) atom. In the ninth O site, O(20) is bonded in a distorted single-bond geometry to one K(2), one Ho(1), and one C(13) atom. In the tenth O site, O(21) is bonded in a distorted bent 120 degrees geometry to one Ho(2) and one C(16) atom. In the eleventh O site, O(22) is bonded in a single-bond geometry to one C(24) atom. In the twelfth O site, O(1) is bonded in a 1-coordinate geometry to one K(1), one Ho(2), and one C(23) atom. In the thirteenth O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one Ho(1), and one C(6) atom. In the fourteenth O site, O(3) is bonded in a distorted single-bond geometry to one K(3), one Ho(1), and one C(6) atom. In the fifteenth O site, O(4) is bonded in a distorted single-bond geometry to one K(3), one Ho(3), and one C(17) atom. In the sixteenth O site, O(5) is bonded in a single-bond geometry to one C(12) atom. In the seventeenth O site, O(6) is bonded in a bent 120 degrees geometry to one Ho(1) and one C(21) atom. In the eighteenth O site, O(7) is bonded in a 1-coordinate geometry to one K(3), one Ho(1), and one C(10) atom. In the nineteenth O site, O(8) is bonded in a single-bond geometry to one C(21) atom. In the twentieth O site, O(9) is bonded in a 1-coordinate geometry to one K(1), one Ho(1), and one C(23) atom. In the twenty-first O site, O(10) is bonded in a 3-coordinate geometry to one K(2), one Ho(2), and one C(11) atom. In the twenty-second O site, O(11) is bonded in a distorted single-bond geometry to one K(2), one Ho(2), and one C(20) atom. Linkers: 20 [O]C(=O)c1nc(C([O])=O)c(C([O])=O)nc1C([O])=O. Metal clusters: 20 [K] ,20 [Ho]. The MOF has largest included sphere 4.39 A, density 2.07 g/cm3, surface area 2176.75 m2/g, accessible volume 0.15 cm3/g