BaZnH16(CO)10 crystallizes in the trigonal R-3m space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(5) atoms. Both Ba(1)-O(3) bond lengths are 2.91 Å. Both Ba(1)-O(4) bond lengths are 2.82 Å. There are two shorter (2.85 Å) and two longer (2.89 Å) Ba(1)-O(5) bond lengths. Zn(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Zn(1)-O(1) bond lengths are 2.01 Å. Both Zn(1)-O(3) bond lengths are 2.04 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(1), and one O(2) atom. The C(1)-C(3) bond length is 1.54 Å. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.23 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(3), and one O(4) atom. The C(2)-C(6) bond length is 1.55 Å. The C(2)-O(3) bond length is 1.27 Å. The C(2)-O(4) bond length is 1.24 Å. In the third C site, C(3) is bonded in a tetrahedral geometry to one C(4), one C(5), and two equivalent C(1) atoms. The C(3)-C(4) bond length is 1.52 Å. The C(3)-C(5) bond length is 1.54 Å. In the fourth C site, C(4) is bonded in a trigonal non-coplanar geometry to one C(3), one H(7), and two equivalent H(3) atoms. The C(4)-H(7) bond length is 0.96 Å. Both C(4)-H(3) bond lengths are 0.96 Å. In the fifth C site, C(5) is bonded in a trigonal non-coplanar geometry to one C(3), one H(8), and two equivalent H(4) atoms. The C(5)-H(8) bond length is 0.96 Å. Both C(5)-H(4) bond lengths are 0.96 Å. In the sixth C site, C(6) is bonded in a tetrahedral geometry to one C(7), one C(8), and two equivalent C(2) atoms. The C(6)-C(7) bond length is 1.52 Å. The C(6)-C(8) bond length is 1.54 Å. In the seventh C site, C(7) is bonded in a trigonal non-coplanar geometry to one C(6); one H(9,10); and two equivalent H(5,6) atoms. The C(7)-H(9,10) bond length is 0.96 Å. Both C(7)-H(5,6) bond lengths are 0.96 Å. In the eighth C site, C(8) is bonded in a trigonal non-coplanar geometry to one C(6); one H(9,10); and two equivalent H(5,6) atoms. The C(8)-H(9,10) bond length is 0.96 Å. Both C(8)-H(5,6) bond lengths are 0.96 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.84 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.84 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(5) atom. In the fifth H site, H(5,6) is bonded in a single-bond geometry to one C(7) atom. In the sixth H site, H(7) is bonded in a single-bond geometry to one C(4) atom. In the seventh H site, H(8) is bonded in a single-bond geometry to one C(5) atom. In the eighth H site, H(9,10) is bonded in a single-bond geometry to one C(7) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Zn(1) and one C(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one C(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(1), one Zn(1), and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1) and one C(2) atom. In the fifth O site, O(5) is bonded in a water-like geometry to two equivalent Ba(1), one H(1), and one H(2) atom. Linkers: 18 CC(C)(C([O])=O)C([O])=O. Metal clusters: 18 [Ba] ,18 [Zn]. The MOF has largest included sphere 5.11 A, density 1.76 g/cm3, surface area 3598.30 m2/g, accessible volume 0.22 cm3/g