Ca2C14N2H20O15 crystallizes in the monoclinic P2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(5), one O(6), one O(7), one O(8), two equivalent O(3), and two equivalent O(4) atoms. The Ca(1)-O(5) bond length is 2.51 Å. The Ca(1)-O(6) bond length is 2.62 Å. The Ca(1)-O(7) bond length is 2.41 Å. The Ca(1)-O(8) bond length is 2.36 Å. There is one shorter (2.41 Å) and one longer (2.71 Å) Ca(1)-O(3) bond length. There is one shorter (2.38 Å) and one longer (2.45 Å) Ca(1)-O(4) bond length. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one N(1), and one H(3) atom. The C(1)-C(2) bond length is 1.40 Å. The C(1)-N(1) bond length is 1.34 Å. The C(1)-H(3) bond length is 1.09 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(6) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(6) bond length is 1.50 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(7) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-C(7) bond length is 1.51 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one H(1) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-H(1) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one H(2) atom. The C(5)-N(1) bond length is 1.35 Å. The C(5)-H(2) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(6)-O(3) bond length is 1.27 Å. The C(6)-O(4) bond length is 1.27 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(1), and one O(2) atom. The C(7)-O(1) bond length is 1.28 Å. The C(7)-O(2) bond length is 1.27 Å. N(1) is bonded in a distorted trigonal planar geometry to one C(1), one C(5), and one H(6) atom. The N(1)-H(6) bond length is 1.74 Å. There are ten inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(4) 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(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one O(1) and one O(5) atom. The H(4)-O(1) bond length is 1.60 Å. The H(4)-O(5) 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 0.98 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one N(1) and one O(7) atom. The H(6)-O(7) bond length is 1.02 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(7) atom. The H(7)-O(7) bond length is 0.99 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(2) and one O(6) atom. The H(8)-O(2) bond length is 1.69 Å. The H(8)-O(6) bond length is 1.00 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(2) and one O(8) atom. The H(9)-O(2) bond length is 1.72 Å. The H(9)-O(8) 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 0.98 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one C(7) and one H(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one C(7), one H(8), and one H(9) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(6) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ca(1) and one C(6) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one Ca(1), one H(4), and one H(5) atom. In the sixth O site, O(6) is bonded in a water-like geometry to two equivalent Ca(1) and two equivalent H(8) atoms. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Ca(1), one H(6), and one H(7) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Ca(1), one H(10), and one H(9) atom. Linkers: 4 [O]C(=O)c1ccncc1C([O])=O ,2 O. Metal clusters: 4 [Ca]. The MOF has largest included sphere 2.68 A, density 1.69 g/cm3, surface area 3896.06 m2/g, accessible volume 0.09 cm3/g