NaBH11(CO2)4 is Indium-like structured and crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four NaBH11(CO2)4 clusters. Na(1) is bonded in a 7-coordinate geometry to one H(1), one O(1), one O(3), one O(7), one O(8), and two equivalent O(6) atoms. The Na(1)-H(1) bond length is 2.53 Å. The Na(1)-O(1) bond length is 2.67 Å. The Na(1)-O(3) bond length is 2.37 Å. The Na(1)-O(7) bond length is 2.64 Å. The Na(1)-O(8) bond length is 2.42 Å. There is one shorter (2.33 Å) and one longer (2.47 Å) Na(1)-O(6) bond length. B(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. The B(1)-O(3) bond length is 1.37 Å. The B(1)-O(4) bond length is 1.39 Å. The B(1)-O(5) bond length is 1.38 Å. There are four 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 1.50 Å. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(2) bond length is 1.30 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(4) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(4) 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) and one H(1) atom. The C(3)-H(1) bond length is 1.08 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(2) and one H(2) atom. The C(4)-H(2) bond length is 1.09 Å. There are eleven inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one Na(1) and one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a distorted linear geometry to one O(1) and one O(3) atom. The H(3)-O(1) bond length is 1.62 Å. The H(3)-O(3) bond length is 1.01 Å. In the fourth H site, H(4) is bonded in a linear geometry to one O(2) and one O(4) atom. The H(4)-O(2) bond length is 1.53 Å. The H(4)-O(4) bond length is 1.03 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(5) atom. The H(5)-O(5) bond length is 0.99 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(6) atom. The H(6)-O(6) bond length is 0.99 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(6) atom. The H(7)-O(6) bond length is 0.99 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(7) atom. The H(8)-O(7) bond length is 0.99 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(7) atom. The H(9)-O(7) bond length is 0.99 Å. In the tenth H site, H(10) is bonded in a single-bond geometry to one O(8) atom. The H(10)-O(8) bond length is 1.00 Å. In the eleventh H site, H(11) is bonded in a single-bond geometry to one O(8) atom. The H(11)-O(8) bond length is 0.99 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one C(1), and one H(3) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one C(1) and one H(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one B(1), and one H(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one B(1) and one H(4) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one B(1) and one H(5) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to two equivalent Na(1), one H(6), and one H(7) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one Na(1), one H(8), and one H(9) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Na(1), one H(10), and one H(11) atom. Linkers: 2 [O]C(=O)c1ccc(C([O])=O)cc1. Metal clusters: 4 [Na]. The MOF has largest included sphere 1.73 A, density 1.64 g/cm3, surface area 3704.75 m2/g, accessible volume 0.07 cm3/g