MnH4(CN)8 crystallizes in the monoclinic P2_1/c space group. The structure consists of a MnH4(CN)8 framework. Mn(1) is bonded in an octahedral geometry to one N(1), one N(3), one N(4), one N(6), one N(7), and one N(8) atom. The Mn(1)-N(1) bond length is 2.13 Å. The Mn(1)-N(3) bond length is 2.18 Å. The Mn(1)-N(4) bond length is 2.15 Å. The Mn(1)-N(6) bond length is 2.18 Å. The Mn(1)-N(7) bond length is 2.27 Å. The Mn(1)-N(8) bond length is 2.27 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a linear geometry to one N(1) and one N(2) atom. The C(1)-N(1) bond length is 1.18 Å. The C(1)-N(2) bond length is 1.29 Å. In the second C site, C(2) is bonded in a linear geometry to one N(2) and one N(3) atom. The C(2)-N(2) bond length is 1.29 Å. The C(2)-N(3) bond length is 1.18 Å. In the third C site, C(3) is bonded in a linear geometry to one N(4) and one N(5) atom. The C(3)-N(4) bond length is 1.18 Å. The C(3)-N(5) bond length is 1.29 Å. In the fourth C site, C(4) is bonded in a linear geometry to one N(5) and one N(6) atom. The C(4)-N(5) bond length is 1.29 Å. The C(4)-N(6) bond length is 1.18 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(6), one N(7), and one H(1) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-N(7) bond length is 1.34 Å. The C(5)-H(1) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one N(8), and one H(2) atom. The C(6)-N(8) bond length is 1.34 Å. The C(6)-H(2) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(8), one N(8), and one H(3) atom. The C(7)-C(8) bond length is 1.39 Å. The C(7)-N(8) bond length is 1.34 Å. The C(7)-H(3) bond length is 1.09 Å. In the eighth C site, C(8) is bonded in a distorted trigonal planar geometry to one C(7), one N(7), and one H(4) atom. The C(8)-N(7) bond length is 1.34 Å. The C(8)-H(4) bond length is 1.09 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a linear geometry to one Mn(1) and one C(1) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one C(1) and one C(2) atom. In the third N site, N(3) is bonded in a bent 150 degrees geometry to one Mn(1) and one C(2) atom. In the fourth N site, N(4) is bonded in a bent 150 degrees geometry to one Mn(1) and one C(3) atom. In the fifth N site, N(5) is bonded in a bent 120 degrees geometry to one C(3) and one C(4) atom. In the sixth N site, N(6) is bonded in a bent 150 degrees geometry to one Mn(1) and one C(4) atom. In the seventh N site, N(7) is bonded in a trigonal planar geometry to one Mn(1), one C(5), and one C(8) atom. In the eighth N site, N(8) is bonded in a trigonal planar geometry to one Mn(1), one C(6), and one C(7) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(5) 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(8) atom. Linkers: 4 c1cnccn1. Metal clusters: 4 [Mn]. The MOF has largest included sphere 1.82 A, density 1.66 g/cm3, surface area 4549.69 m2/g, accessible volume 0.13 cm3/g