Na3Fe2H12(C2O)16 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(13), one O(2), one O(6), and one O(7) atom. The Na(1)-O(1) bond length is 2.67 Å. The Na(1)-O(11) bond length is 2.37 Å. The Na(1)-O(13) bond length is 2.46 Å. The Na(1)-O(2) bond length is 2.31 Å. The Na(1)-O(6) bond length is 2.27 Å. The Na(1)-O(7) bond length is 2.31 Å. In the second Na site, Na(2) is bonded to one O(14), one O(16), one O(5), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra and  a cornercorner with one Fe(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 75°. The Na(2)-O(14) bond length is 2.26 Å. The Na(2)-O(16) bond length is 2.28 Å. The Na(2)-O(5) bond length is 2.24 Å. The Na(2)-O(9) bond length is 2.27 Å. In the third Na site, Na(3) is bonded in a distorted T-shaped geometry to one O(1), one O(11), and one O(3) atom. The Na(3)-O(1) bond length is 2.69 Å. The Na(3)-O(11) bond length is 2.51 Å. The Na(3)-O(3) bond length is 2.59 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(12), one O(13), one O(4), one O(7), and one O(9) atom to form distorted FeO6 pentagonal pyramids that share  a cornercorner with one Na(2)O4 tetrahedra. The Fe(1)-O(10) bond length is 1.95 Å. The Fe(1)-O(12) bond length is 2.17 Å. The Fe(1)-O(13) bond length is 1.98 Å. The Fe(1)-O(4) bond length is 2.23 Å. The Fe(1)-O(7) bond length is 2.12 Å. The Fe(1)-O(9) bond length is 2.17 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(15), one O(3), one O(5), one O(6), and one O(8) atom to form distorted FeO6 octahedra that share  a cornercorner with one Na(2)O4 tetrahedra. The Fe(2)-O(1) bond length is 2.01 Å. The Fe(2)-O(15) bond length is 1.98 Å. The Fe(2)-O(3) bond length is 2.19 Å. The Fe(2)-O(5) bond length is 2.14 Å. The Fe(2)-O(6) bond length is 2.15 Å. The Fe(2)-O(8) bond length is 2.20 Å. There are thirty-two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(14), one O(1), and one O(2) atom. The C(1)-C(14) bond length is 1.48 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.21 Å. In the second C site, C(2) is bonded in a bent 120 degrees geometry to one C(8), one O(14), and one O(15) atom. The C(2)-C(8) bond length is 1.48 Å. The C(2)-O(14) bond length is 1.23 Å. The C(2)-O(15) bond length is 1.25 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(16), one C(30), and one C(7) atom. The C(3)-C(16) bond length is 1.37 Å. The C(3)-C(30) bond length is 1.48 Å. The C(3)-C(7) bond length is 1.38 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(29), one C(8), and one H(1) atom. The C(4)-C(29) bond length is 1.36 Å. The C(4)-C(8) bond length is 1.32 Å. The C(4)-H(1) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(21), one C(27), and one C(28) atom. The C(5)-C(21) bond length is 1.39 Å. The C(5)-C(27) bond length is 1.38 Å. The C(5)-C(28) bond length is 1.50 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(13), one C(14), and one H(2) atom. The C(6)-C(13) bond length is 1.36 Å. The C(6)-C(14) bond length is 1.36 Å. The C(6)-H(2) bond length is 0.93 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(29), one C(3), and one H(3) atom. The C(7)-C(29) bond length is 1.37 Å. The C(7)-H(3) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(16), one C(2), and one C(4) atom. The C(8)-C(16) bond length is 1.37 Å. In the ninth C site, C(9) is bonded in a bent 120 degrees geometry to one C(18), one O(4), and one O(7) atom. The C(9)-C(18) bond length is 1.49 Å. The C(9)-O(4) bond length is 1.23 Å. The C(9)-O(7) bond length is 1.24 Å. In the tenth C site, C(10) is bonded in a bent 120 degrees geometry to one C(20), one O(3), and one O(5) atom. The C(10)-C(20) bond length is 1.47 Å. The C(10)-O(3) bond length is 1.26 Å. The C(10)-O(5) bond length is 1.22 Å. In the eleventh C site, C(11) is bonded in a trigonal planar geometry to one C(12), one C(15), and one C(23) atom. The C(11)-C(12) bond length is 1.38 Å. The C(11)-C(15) bond length is 1.48 Å. The C(11)-C(23) bond length is 1.36 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(11), one C(13), and one H(4) atom. The C(12)-C(13) bond length is 1.34 Å. The C(12)-H(4) bond length is 0.93 Å. In the thirteenth C site, C(13) is bonded in a trigonal planar geometry to one C(12), one C(22), and one C(6) atom. The C(13)-C(22) bond length is 1.46 Å. In the fourteenth C site, C(14) is bonded in a trigonal planar geometry to one C(1), one C(23), and one C(6) atom. The C(14)-C(23) bond length is 1.37 Å. In the fifteenth C site, C(15) is bonded in a trigonal planar geometry to one C(11), one C(19), and one C(21) atom. The C(15)-C(19) bond length is 1.36 Å. The C(15)-C(21) bond length is 1.36 Å. In the sixteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(3), one C(8), and one H(5) atom. The C(16)-H(5) bond length is 0.93 Å. In the seventeenth C site, C(17) is bonded in a distorted single-bond geometry to one C(18), one C(20), and one H(6) atom. The C(17)-C(18) bond length is 1.35 Å. The C(17)-C(20) bond length is 1.36 Å. The C(17)-H(6) bond length is 0.93 Å. In the eighteenth C site, C(18) is bonded in a trigonal planar geometry to one C(17), one C(26), and one C(9) atom. The C(18)-C(26) bond length is 1.37 Å. In the nineteenth C site, C(19) is bonded in a distorted single-bond geometry to one C(15), one C(25), and one H(7) atom. The C(19)-C(25) bond length is 1.37 Å. The C(19)-H(7) bond length is 0.93 Å. In the twentieth C site, C(20) is bonded in a trigonal planar geometry to one C(10), one C(17), and one C(32) atom. The C(20)-C(32) bond length is 1.37 Å. In the twenty-first C site, C(21) is bonded in a single-bond geometry to one C(15), one C(5), and one H(8) atom. The C(21)-H(8) bond length is 0.93 Å. In the twenty-second C site, C(22) is bonded in a bent 120 degrees geometry to one C(13), one O(6), and one O(8) atom. The C(22)-O(6) bond length is 1.27 Å. The C(22)-O(8) bond length is 1.22 Å. In the twenty-third C site, C(23) is bonded in a distorted single-bond geometry to one C(11), one C(14), and one H(9) atom. The C(23)-H(9) bond length is 0.93 Å. In the twenty-fourth C site, C(24) is bonded in a bent 120 degrees geometry to one C(25), one O(12), and one O(9) atom. The C(24)-C(25) bond length is 1.50 Å. The C(24)-O(12) bond length is 1.23 Å. The C(24)-O(9) bond length is 1.25 Å. In the twenty-fifth C site, C(25) is bonded in a trigonal planar geometry to one C(19), one C(24), and one C(27) atom. The C(25)-C(27) bond length is 1.37 Å. In the twenty-sixth C site, C(26) is bonded in a single-bond geometry to one C(18), one C(31), and one H(10) atom. The C(26)-C(31) bond length is 1.35 Å. The C(26)-H(10) bond length is 0.93 Å. In the twenty-seventh C site, C(27) is bonded in a distorted single-bond geometry to one C(25), one C(5), and one H(11) atom. The C(27)-H(11) bond length is 0.93 Å. In the twenty-eighth C site, C(28) is bonded in a bent 120 degrees geometry to one C(5), one O(10), and one O(16) atom. The C(28)-O(10) bond length is 1.24 Å. The C(28)-O(16) bond length is 1.21 Å. In the twenty-ninth C site, C(29) is bonded in a trigonal planar geometry to one C(31), one C(4), and one C(7) atom. The C(29)-C(31) bond length is 1.49 Å. In the thirtieth C site, C(30) is bonded in a bent 120 degrees geometry to one C(3), one O(11), and one O(13) atom. The C(30)-O(11) bond length is 1.23 Å. The C(30)-O(13) bond length is 1.24 Å. In the thirty-first C site, C(31) is bonded in a trigonal planar geometry to one C(26), one C(29), and one C(32) atom. The C(31)-C(32) bond length is 1.40 Å. In the thirty-second C site, C(32) is bonded in a single-bond geometry to one C(20), one C(31), and one H(12) atom. The C(32)-H(12) bond length is 0.93 Å. There are twelve 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(2) is bonded in a single-bond geometry to one C(6) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(12) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(16) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(17) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(19) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(21) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(23) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(26) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one C(27) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one C(32) atom. There are sixteen inequivalent O sites. In the first O site, O(9) is bonded in a distorted T-shaped geometry to one Na(2), one Fe(1), and one C(24) atom. In the second O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one C(28) atom. In the third O site, O(11) is bonded in a distorted T-shaped geometry to one Na(1), one Na(3), and one C(30) atom. In the fourth O site, O(12) is bonded in an L-shaped geometry to one Fe(1) and one C(24) atom. In the fifth O site, O(13) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(1), and one C(30) atom. In the sixth O site, O(14) is bonded in a bent 120 degrees geometry to one Na(2) and one C(2) atom. In the seventh O site, O(15) is bonded in a bent 150 degrees geometry to one Fe(2) and one C(2) atom. In the eighth O site, O(16) is bonded in a water-like geometry to one Na(2) and one C(28) atom. In the ninth O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Fe(2), and one C(1) atom. In the tenth O site, O(2) is bonded in a water-like geometry to one Na(1) and one C(1) atom. In the eleventh O site, O(3) is bonded in a distorted T-shaped geometry to one Na(3), one Fe(2), and one C(10) atom. In the twelfth O site, O(4) is bonded in an L-shaped geometry to one Fe(1) and one C(9) atom. In the thirteenth O site, O(5) is bonded in a distorted T-shaped geometry to one Na(2), one Fe(2), and one C(10) atom. In the fourteenth O site, O(6) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(2), and one C(22) atom. In the fifteenth O site, O(7) is bonded in a distorted T-shaped geometry to one Na(1), one Fe(1), and one C(9) atom. In the sixteenth O site, O(8) is bonded in an L-shaped geometry to one Fe(2) and one C(22) atom. Linkers: 8 [O]C(=O)c1cc(C([O])=O)cc(-c2cc(C([O])=O)cc(C([O])=O)c2)c1. Metal clusters: 12 [Na] ,8 [Fe]. The MOF has largest included sphere 6.81 A, density 1.09 g/cm3, surface area 3507.98 m2/g, accessible volume 0.43 cm3/g