FeC4H8O7 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in an octahedral geometry to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom. The Fe(1)-O(1) bond length is 2.22 Å. The Fe(1)-O(11) bond length is 2.14 Å. The Fe(1)-O(3) bond length is 2.13 Å. The Fe(1)-O(5) bond length is 2.00 Å. The Fe(1)-O(7) bond length is 2.10 Å. The Fe(1)-O(9) bond length is 2.18 Å. In the second Fe site, Fe(2) is bonded in an octahedral geometry to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom. The Fe(2)-O(10) bond length is 2.17 Å. The Fe(2)-O(12) bond length is 2.14 Å. The Fe(2)-O(2) bond length is 2.22 Å. The Fe(2)-O(4) bond length is 2.13 Å. The Fe(2)-O(6) bond length is 2.00 Å. The Fe(2)-O(8) bond length is 2.11 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 O(5) and one O(7) atom. The C(1)-O(5) bond length is 1.28 Å. The C(1)-O(7) bond length is 1.26 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(6) and one O(8) atom. The C(2)-O(6) bond length is 1.28 Å. The C(2)-O(8) bond length is 1.26 Å. In the third C site, C(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent H(1,3) and one O(9) atom. Both C(3)-H(1,3) bond lengths are 1.10 Å. The C(3)-O(9) bond length is 1.42 Å. In the fourth C site, C(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent H(2,4) and one O(10) atom. Both C(4)-H(2,4) bond lengths are 1.10 Å. The C(4)-O(10) bond length is 1.42 Å. In the fifth C site, C(5) is bonded in a distorted trigonal non-coplanar geometry to one H(5), one H(7), and one O(9) atom. The C(5)-H(5) bond length is 1.10 Å. The C(5)-H(7) bond length is 1.10 Å. The C(5)-O(9) bond length is 1.43 Å. In the sixth C site, C(6) is bonded in a distorted trigonal non-coplanar geometry to one H(6), one H(8), and one O(10) atom. The C(6)-H(6) bond length is 1.10 Å. The C(6)-H(8) bond length is 1.10 Å. The C(6)-O(10) bond length is 1.43 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one O(11) and one O(13) atom. The C(7)-O(11) bond length is 1.28 Å. The C(7)-O(13) bond length is 1.26 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one O(12) and one O(14) atom. The C(8)-O(12) bond length is 1.28 Å. The C(8)-O(14) bond length is 1.26 Å. There are fourteen inequivalent H sites. In the first H site, H(1,3) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2,4) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(5) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(6) is bonded in a single-bond geometry to one C(6) atom. In the fifth H site, H(7) is bonded in a single-bond geometry to one C(5) atom. In the sixth H site, H(8) is bonded in a single-bond geometry to one C(6) atom. In the seventh H site, H(9) is bonded in a distorted single-bond geometry to one O(1) and one O(14) atom. The H(9)-O(1) bond length is 1.00 Å. The H(9)-O(14) bond length is 1.67 Å. In the eighth H site, H(10) is bonded in a distorted single-bond geometry to one O(13) and one O(2) atom. The H(10)-O(13) bond length is 1.67 Å. The H(10)-O(2) bond length is 1.00 Å. In the ninth H site, H(11) is bonded in a single-bond geometry to one O(1) atom. The H(11)-O(1) bond length is 0.98 Å. In the tenth H site, H(12) is bonded in a single-bond geometry to one O(2) atom. The H(12)-O(2) bond length is 0.98 Å. In the eleventh H site, H(13) is bonded in a distorted single-bond geometry to one O(13) and one O(3) atom. The H(13)-O(13) bond length is 1.67 Å. The H(13)-O(3) bond length is 1.00 Å. In the twelfth H site, H(14) is bonded in a distorted single-bond geometry to one O(14) and one O(4) atom. The H(14)-O(14) bond length is 1.67 Å. The H(14)-O(4) bond length is 1.00 Å. In the thirteenth H site, H(15) is bonded in a distorted single-bond geometry to one O(12) and one O(3) atom. The H(15)-O(12) bond length is 1.68 Å. The H(15)-O(3) bond length is 1.00 Å. In the fourteenth H site, H(16) is bonded in a distorted single-bond geometry to one O(11) and one O(4) atom. The H(16)-O(11) bond length is 1.68 Å. The H(16)-O(4) bond length is 1.00 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Fe(1), one H(11), and one H(9) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Fe(2), one H(10), and one H(12) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Fe(1), one H(13), and one H(15) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Fe(2), one H(14), and one H(16) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one C(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one C(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(2) and one C(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(1), one C(3), and one C(5) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(2), one C(4), and one C(6) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one C(7), and one H(16) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2), one C(8), and one H(15) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one C(7), one H(10), and one H(13) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one C(8), one H(14), and one H(9) atom. Linkers: 4 [O]C(=O)COCC([O])=O. Metal clusters: 4 [Fe]. The MOF has largest included sphere 1.72 A, density 1.96 g/cm3, surface area 3577.54 m2/g, accessible volume 0.11 cm3/g