Na3CuZn4H4(CO)20 crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in an L-shaped geometry to one O(1) and one O(3) atom. The Na(1)-O(1) bond length is 2.30 Å. The Na(1)-O(3) bond length is 2.44 Å. In the second Na site, Na(2) is bonded in a 2-coordinate geometry to two equivalent O(8) atoms. Both Na(2)-O(8) bond lengths are 2.57 Å. Cu(1) is bonded to two equivalent O(10), two equivalent O(7), and two equivalent O(9) atoms to form distorted CuO6 octahedra that share corners with two equivalent Zn(2)O4 tetrahedra, edges with two equivalent Zn(3)O6 octahedra, and edges with two equivalent Zn(1)O5 trigonal bipyramids. Both Cu(1)-O(10) bond lengths are 2.00 Å. Both Cu(1)-O(7) bond lengths are 2.50 Å. Both Cu(1)-O(9) bond lengths are 1.93 Å. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(2), one O(3), one O(5), one O(7), and one O(9) atom to form distorted ZnO5 trigonal bipyramids that share  a cornercorner with one Zn(3)O6 octahedra and  an edgeedge with one Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 69°. The Zn(1)-O(2) bond length is 1.96 Å. The Zn(1)-O(3) bond length is 2.00 Å. The Zn(1)-O(5) bond length is 2.10 Å. The Zn(1)-O(7) bond length is 2.32 Å. The Zn(1)-O(9) bond length is 2.01 Å. In the second Zn site, Zn(2) is bonded to two equivalent O(10) and two equivalent O(8) atoms to form distorted ZnO4 tetrahedra that share corners with two equivalent Cu(1)O6 octahedra and  an edgeedge with one Zn(3)O6 octahedra. The corner-sharing octahedral tilt angles are 63°. Both Zn(2)-O(10) bond lengths are 1.97 Å. Both Zn(2)-O(8) bond lengths are 1.97 Å. In the third Zn site, Zn(3) is bonded to two equivalent O(10), two equivalent O(6), and two equivalent O(9) atoms to form ZnO6 octahedra that share corners with two equivalent Zn(1)O5 trigonal bipyramids, edges with two equivalent Cu(1)O6 octahedra, and  an edgeedge with one Zn(2)O4 tetrahedra. Both Zn(3)-O(10) bond lengths are 2.28 Å. Both Zn(3)-O(6) bond lengths are 2.03 Å. Both Zn(3)-O(9) bond lengths are 2.02 Å. There are ten inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one C(7) atom. The C(1)-C(2) bond length is 1.39 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-C(7) bond length is 1.50 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(8) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-C(8) bond length is 1.50 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 1.37 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(9) atom. The C(4)-C(5) bond length is 1.41 Å. The C(4)-C(9) bond length is 1.51 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(10), one C(4), and one C(6) atom. The C(5)-C(10) bond length is 1.50 Å. The C(5)-C(6) bond length is 1.37 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(2) atom. The C(6)-H(2) bond length is 0.93 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(7)-O(1) bond length is 1.23 Å. The C(7)-O(2) bond length is 1.27 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.28 Å. The C(8)-O(4) bond length is 1.24 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(5), and one O(6) atom. The C(9)-O(5) bond length is 1.25 Å. The C(9)-O(6) bond length is 1.25 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(7), and one O(8) atom. The C(10)-O(7) bond length is 1.25 Å. The C(10)-O(8) bond length is 1.27 Å. There are two 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(6) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one C(7) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(7) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Zn(1), and one C(8) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one C(8) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Zn(1) and one C(9) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Zn(3) and one C(9) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Cu(1), one Zn(1), and one C(10) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(2), one Zn(2), and one C(10) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Cu(1), one Zn(1), and one Zn(3) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Cu(1), one Zn(2), and one Zn(3) atom. Linkers: 4 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 6 [Na] ,8 [Zn] ,2 [Cu]. The MOF has largest included sphere 4.11 A, density 1.77 g/cm3, surface area 3134.79 m2/g, accessible volume 0.22 cm3/g