MnH2(C2O)3 crystallizes in the triclinic P-1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(4), one O(6), one O(7), and one O(8) atom to form distorted edge-sharing MnO5 square pyramids. The Mn(1)-O(2) bond length is 2.06 Å. The Mn(1)-O(4) bond length is 2.19 Å. The Mn(1)-O(6) bond length is 2.11 Å. The Mn(1)-O(7) bond length is 2.12 Å. The Mn(1)-O(8) bond length is 2.07 Å. In the second Mn site, Mn(2) is bonded to one O(3), one O(4), one O(5), one O(8), and one O(9) atom to form distorted edge-sharing MnO5 square pyramids. The Mn(2)-O(3) bond length is 2.06 Å. The Mn(2)-O(4) bond length is 2.11 Å. The Mn(2)-O(5) bond length is 2.19 Å. The Mn(2)-O(8) bond length is 2.12 Å. The Mn(2)-O(9) bond length is 2.07 Å. In the third Mn site, Mn(3) is bonded to one O(1), one O(5), one O(6), one O(7), and one O(9) atom to form distorted edge-sharing MnO5 square pyramids. The Mn(3)-O(1) bond length is 2.06 Å. The Mn(3)-O(5) bond length is 2.11 Å. The Mn(3)-O(6) bond length is 2.19 Å. The Mn(3)-O(7) bond length is 2.07 Å. The Mn(3)-O(9) bond length is 2.12 Å. There are sixteen inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one C(4), one O(1), and one O(4) atom. The C(1)-C(4) bond length is 1.47 Å. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(4) bond length is 1.30 Å. In the second C site, C(2) is bonded in a bent 120 degrees geometry to one C(5,6); one O(2); and one O(5) atom. The C(2)-C(5,6) bond length is 1.47 Å. The C(2)-O(2) bond length is 1.28 Å. The C(2)-O(5) bond length is 1.30 Å. In the third C site, C(3) is bonded in a bent 120 degrees geometry to one C(5,6); one O(3); and one O(6) atom. The C(3)-C(5,6) bond length is 1.47 Å. The C(3)-O(3) bond length is 1.28 Å. The C(3)-O(6) bond length is 1.30 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(1); one C(10,12); and one C(7) atom. The C(4)-C(10,12) bond length is 1.42 Å. The C(4)-C(7) bond length is 1.42 Å. In the fifth C site, C(5,6) is bonded in a trigonal planar geometry to one C(11), one C(2), and one C(8) atom. The C(5,6)-C(11) bond length is 1.42 Å. The C(5,6)-C(8) bond length is 1.42 Å. In the sixth C site, C(7) is bonded in a single-bond geometry to one C(16), one C(4), and one O(7) atom. The C(7)-C(16) bond length is 1.44 Å. The C(7)-O(7) bond length is 1.34 Å. In the seventh C site, C(8) is bonded in a single-bond geometry to one C(17); one C(5,6); and one O(8) atom. The C(8)-C(17) bond length is 1.44 Å. The C(8)-O(8) bond length is 1.34 Å. In the eighth C site, C(9) is bonded in a single-bond geometry to one C(18); one C(5,6); and one O(9) atom. The C(9)-C(18) bond length is 1.44 Å. The C(9)-C(5,6) bond length is 1.42 Å. The C(9)-O(9) bond length is 1.34 Å. In the ninth C site, C(10,12) is bonded in a distorted trigonal planar geometry to one C(13), one C(4), and one H(1) atom. The C(10,12)-C(13) bond length is 1.37 Å. The C(10,12)-H(1) bond length is 1.09 Å. In the tenth C site, C(11) is bonded in a distorted trigonal planar geometry to one C(14); one C(5,6); and one H(2,3) atom. The C(11)-C(14) bond length is 1.37 Å. The C(11)-H(2,3) bond length is 1.09 Å. In the eleventh C site, C(13) is bonded in a distorted trigonal planar geometry to one C(10,12); one C(16); and one H(4,5,6) atom. The C(13)-C(16) bond length is 1.42 Å. The C(13)-H(4,5,6) bond length is 1.09 Å. In the twelfth C site, C(14) is bonded in a distorted trigonal planar geometry to one C(11); one C(17); and one H(4,5,6) atom. The C(14)-C(17) bond length is 1.42 Å. The C(14)-H(4,5,6) bond length is 1.09 Å. In the thirteenth C site, C(15) is bonded in a distorted trigonal planar geometry to one C(10,12); one C(18); and one H(4,5,6) atom. The C(15)-C(10,12) bond length is 1.37 Å. The C(15)-C(18) bond length is 1.42 Å. The C(15)-H(4,5,6) bond length is 1.09 Å. In the fourteenth C site, C(16) is bonded in a trigonal planar geometry to one C(13), one C(16), and one C(7) atom. The C(16)-C(16) bond length is 1.43 Å. In the fifteenth C site, C(17) is bonded in a trigonal planar geometry to one C(14), one C(17), and one C(8) atom. The C(17)-C(17) bond length is 1.43 Å. In the sixteenth C site, C(18) is bonded in a trigonal planar geometry to one C(15), one C(18), and one C(9) atom. The C(18)-C(18) bond length is 1.43 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(10,12) atom. In the second H site, H(2,3) is bonded in a single-bond geometry to one C(11) atom. In the third H site, H(4,5,6) is bonded in a single-bond geometry to one C(13) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Mn(3) and one C(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(2) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one C(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one C(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mn(2), one Mn(3), and one C(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(3), and one C(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one C(7) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one C(8) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mn(2), one Mn(3), and one C(9) atom. Linkers: 3 [O]C(=O)c1ccc2c([O])c(C([O])=O)ccc2c1[O] ,2 [O][C]c1[c]cc2c([O])c(C([O])=O)ccc2c1[O]. Metal clusters: 6 [Mn]. The MOF has largest included sphere 13.02 A, density 0.99 g/cm3, surface area 2789.76 m2/g, accessible volume 0.75 cm3/g