Mn3H4(C5O4)4 crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in an octahedral geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Mn(1)-O(2) bond length is 2.11 Å. The Mn(1)-O(3) bond length is 2.22 Å. The Mn(1)-O(4) bond length is 2.22 Å. The Mn(1)-O(5) bond length is 2.20 Å. The Mn(1)-O(6) bond length is 2.19 Å. The Mn(1)-O(7) bond length is 2.13 Å. In the second Mn site, Mn(2) is bonded in an L-shaped geometry to two equivalent O(8) atoms. Both Mn(2)-O(8) bond lengths are 2.12 Å. There are ten 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 1.51 Å. The C(1)-O(1) bond length is 1.24 Å. The C(1)-O(2) bond length is 1.27 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 1.40 Å. The C(2)-C(7) bond length is 1.39 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(8) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-C(8) bond length is 1.52 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(1) atom. The C(4)-C(5) bond length is 1.40 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(4), one C(6), and one C(9) atom. The C(5)-C(6) bond length is 1.41 Å. The C(5)-C(9) bond length is 1.52 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(10), one C(5), and one C(7) atom. The C(6)-C(10) bond length is 1.51 Å. The C(6)-C(7) bond length is 1.39 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(2), one C(6), and one H(2) atom. The C(7)-H(2) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.25 Å. The C(8)-O(4) bond length is 1.25 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(5), and one O(6) atom. The C(9)-O(5) bond length is 1.26 Å. The C(9)-O(6) bond length is 1.24 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(7), and one O(8) atom. The C(10)-O(7) bond length is 1.26 Å. The C(10)-O(8) bond length is 1.25 Å. There are two 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(7) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(8) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Mn(1) and one C(8) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(9) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(9) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(10) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mn(2) and one C(10) atom. Linkers: 8 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 12 [Mn]. The MOF has largest included sphere 4.25 A, density 1.37 g/cm3, surface area 3519.34 m2/g, accessible volume 0.31 cm3/g