BaH2(CO)6 crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(9), and two equivalent O(8) atoms. The Ba(1)-O(2) bond length is 2.72 Å. The Ba(1)-O(3) bond length is 2.81 Å. The Ba(1)-O(4) bond length is 2.94 Å. The Ba(1)-O(5) bond length is 2.76 Å. The Ba(1)-O(7) bond length is 2.90 Å. The Ba(1)-O(9) bond length is 2.87 Å. There is one shorter (2.94 Å) and one longer (3.04 Å) Ba(1)-O(8) bond length. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(6), two equivalent O(7), and two equivalent O(9) atoms. Both Ba(2)-O(1) bond lengths are 2.85 Å. Both Ba(2)-O(2) bond lengths are 2.86 Å. Both Ba(2)-O(6) bond lengths are 2.72 Å. Both Ba(2)-O(7) bond lengths are 2.90 Å. Both Ba(2)-O(9) bond lengths are 2.95 Å. There are nine 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 1.49 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.26 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 1.40 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(1) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(8) atom. The C(4)-C(5) bond length is 1.38 Å. The C(4)-C(8) bond length is 1.50 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4), one C(6), and one H(2) atom. The C(5)-C(6) bond length is 1.40 Å. The C(5)-H(2) bond length is 0.93 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(5), one C(7), and one C(9) atom. The C(6)-C(7) bond length is 1.38 Å. The C(6)-C(9) bond length is 1.50 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(3) atom. The C(7)-H(3) 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(4), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.27 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(6), 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 1.26 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(7) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Ba(2) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1) and one C(8) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Ba(1) and one C(8) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(1) and one C(9) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ba(2) and one C(9) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one Ba(1) and one Ba(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to two equivalent Ba(1) atoms. In the ninth O site, O(9) is bonded in a water-like geometry to one Ba(1) and one Ba(2) atom. Linkers: 8 [O]C(=O)c1cc(C([O])=O)cc(C([O])=O)c1. Metal clusters: 12 [Ba]. The MOF has largest included sphere 4.03 A, density 2.12 g/cm3, surface area 2788.17 m2/g, accessible volume 0.11 cm3/g