Hf3FeC48N4H28O12Cl crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. Both Hf(1)-O(3) bond lengths are 2.19 Å. Both Hf(1)-O(4) bond lengths are 2.11 Å. All Hf(1)-O(1) bond lengths are 2.18 Å. In the second Hf site, Hf(2) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Hf(2)-O(2) bond lengths are 2.25 Å. Both Hf(2)-O(3) bond lengths are 2.11 Å. Both Hf(2)-O(4) bond lengths are 2.12 Å. Fe(1) is bonded in a square pyramidal geometry to two equivalent N(1), two equivalent N(2), and one Cl(1) atom. Both Fe(1)-N(1) bond lengths are 2.03 Å. Both Fe(1)-N(2) bond lengths are 1.99 Å. The Fe(1)-Cl(1) bond length is 2.44 Å. There are twelve 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(1), and one O(2) atom. The C(1)-C(2) bond length is 1.52 Å. The C(1)-O(1) bond length is 1.24 Å. The C(1)-O(2) bond length is 1.30 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(7) atom. The C(2)-C(3) bond length is 1.37 Å. The C(2)-C(7) bond length is 1.39 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 H(1) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(1) bond length is 0.94 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(2) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-H(2) bond length is 0.94 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one C(8) atom. The C(5)-C(6) bond length is 1.40 Å. The C(5)-C(8) bond length is 1.54 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(5), one C(7), and one H(3) atom. The C(6)-C(7) bond length is 1.36 Å. The C(6)-H(3) bond length is 0.94 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(2), one C(6), and one H(4) atom. The C(7)-H(4) bond length is 0.94 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(12), one C(5), and one C(9) atom. The C(8)-C(12) bond length is 1.38 Å. The C(8)-C(9) bond length is 1.40 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(10), one C(8), and one N(1) atom. The C(9)-C(10) bond length is 1.44 Å. The C(9)-N(1) bond length is 1.35 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(9) and one H(5) atom. The C(10)-H(5) bond length is 0.94 Å. In the eleventh C site, C(11) is bonded in a distorted water-like geometry to one C(12) and two equivalent H(6,7) atoms. The C(11)-C(12) bond length is 1.41 Å. Both C(11)-H(6,7) bond lengths are 0.98 Å. In the twelfth C site, C(12) is bonded in a distorted trigonal planar geometry to one C(11), one C(8), and one N(2) atom. The C(12)-N(2) bond length is 1.40 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent C(9) atoms. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent C(12) atoms. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(6) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(7) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(10) atom. In the sixth H site, H(6,7) is bonded in a single-bond geometry to one C(11) atom. There are four inequivalent O sites. In the first O site, O(3) is bonded in a trigonal non-coplanar geometry to one Hf(1) and two equivalent Hf(2) atoms. In the second O site, O(4) is bonded in a trigonal non-coplanar geometry to one Hf(1) and two equivalent Hf(2) atoms. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Hf(1) and one C(1) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to one Hf(2) and one C(1) atom. Cl(1) is bonded in a single-bond geometry to one Fe(1) atom. Linkers: 6 [O]C(=O)c1ccc(cc1)C1=C2[CH2]=[CH2]C3=[N]2[Fe]24(n5c1ccc5C(=C1[N]2=C([CH2]=[CH2]1)C(=c1n4c(=C3c2ccc(cc2)C(=O)[O])cc1)c1ccc(cc1)C(=O)[O])c1ccc(cc1)C(=O)[O])Cl. Metal clusters: 1 [C]1O[Hf]23O[C]O[Hf]4567O[C]O[Hf]89O[C]O[Hf]%10%11(O1)(O[C]O[Hf](O[C]O4)(O2)(O3)(O%10)O5)O[C]O[Hf](O[C]O6)(O8)(O9)(O%11)O7 ,2 [C]1O[Hf]23O[C]O[Hf]4567O[C]O[Hf](O[C]O[Hf]89%10(O1)O[C]O[Hf]1(O[C]O4)(O8)(O5)O[Hf](O[C]O9)(O[C]O6)(O%10)(O7)O1)(O2)O3. RCSR code: csq. The MOF has largest included sphere 33.38 A, density 0.56 g/cm3, surface area 2892.93 m2/g, accessible volume 1.44 cm3/g