Ni2C21N2H10O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a rectangular see-saw-like geometry to one N(1), one O(1), one O(4), and one O(9) atom. The Ni(1)-N(1) bond length is 2.08 Å. The Ni(1)-O(1) bond length is 2.03 Å. The Ni(1)-O(4) bond length is 2.06 Å. The Ni(1)-O(9) bond length is 2.04 Å. In the second Ni site, Ni(2) is bonded in a rectangular see-saw-like geometry to one N(2), one O(2), one O(3), and one O(7) atom. The Ni(2)-N(2) bond length is 2.05 Å. The Ni(2)-O(2) bond length is 2.01 Å. The Ni(2)-O(3) bond length is 2.01 Å. The Ni(2)-O(7) bond length is 2.01 Å. There are twenty-one inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(14), one C(2), and one C(6) atom. The C(1)-C(14) bond length is 1.49 Å. The C(1)-C(2) bond length is 1.39 Å. The C(1)-C(6) bond length is 1.39 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1) and one H(1) atom. The C(2)-H(1) bond length is 0.93 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(4) and one H(2) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-H(2) 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(7) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-C(7) bond length is 1.48 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(3) atom. The C(5)-C(6) bond length is 1.41 Å. The C(5)-H(3) bond length is 0.93 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(1), one C(15), and one C(5) atom. The C(6)-C(15) bond length is 1.50 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(4), one C(8), and one O(5) atom. The C(7)-C(8) bond length is 1.50 Å. The C(7)-O(5) bond length is 1.21 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(13), one C(7), and one C(9) atom. The C(8)-C(13) bond length is 1.39 Å. The C(8)-C(9) bond length is 1.39 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(8) and one H(4) atom. The C(9)-H(4) bond length is 0.93 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(11) and one H(5) atom. The C(10)-C(11) bond length is 1.33 Å. The C(10)-H(5) bond length is 0.93 Å. In the eleventh C site, C(11) is bonded in a trigonal planar geometry to one C(10), one C(12), and one C(17) atom. The C(11)-C(12) bond length is 1.42 Å. The C(11)-C(17) bond length is 1.51 Å. In the twelfth C site, C(12) is bonded in a trigonal planar geometry to one C(11), one C(13), and one C(16) atom. The C(12)-C(13) bond length is 1.40 Å. The C(12)-C(16) bond length is 1.47 Å. In the thirteenth C site, C(13) is bonded in a distorted single-bond geometry to one C(12), one C(8), and one H(6) atom. The C(13)-H(6) bond length is 0.93 Å. In the fourteenth C site, C(14) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(14)-O(1) bond length is 1.25 Å. The C(14)-O(2) bond length is 1.23 Å. In the fifteenth C site, C(15) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(3), and one O(4) atom. The C(15)-O(3) bond length is 1.24 Å. The C(15)-O(4) bond length is 1.26 Å. In the sixteenth C site, C(16) is bonded in a distorted bent 120 degrees geometry to one C(12), one O(6), and one O(7) atom. The C(16)-O(6) bond length is 1.24 Å. The C(16)-O(7) bond length is 1.28 Å. In the seventeenth C site, C(17) is bonded in a distorted bent 120 degrees geometry to one C(11), one O(8), and one O(9) atom. The C(17)-O(8) bond length is 1.22 Å. The C(17)-O(9) bond length is 1.29 Å. In the eighteenth C site, C(18) is bonded in a distorted trigonal planar geometry to one C(19), one N(1), and one H(7) atom. The C(18)-C(19) bond length is 1.36 Å. The C(18)-N(1) bond length is 1.33 Å. The C(18)-H(7) bond length is 0.93 Å. In the nineteenth C site, C(19) is bonded in a distorted bent 120 degrees geometry to one C(18), one N(1), and one H(8) atom. The C(19)-N(1) bond length is 1.35 Å. The C(19)-H(8) bond length is 0.93 Å. In the twentieth C site, C(20) is bonded in a distorted bent 120 degrees geometry to one N(2) and one H(9) atom. The C(20)-N(2) bond length is 1.33 Å. The C(20)-H(9) bond length is 0.93 Å. In the twenty-first C site, C(21) is bonded in a distorted bent 120 degrees geometry to one N(2) and one H(10) atom. The C(21)-N(2) bond length is 1.31 Å. The C(21)-H(10) bond length is 0.93 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Ni(1), one C(18), and one C(19) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one Ni(2), one C(20), and one C(21) atom. There are ten inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(9) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(10) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(13) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(18) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(19) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(20) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(21) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ni(1) and one C(14) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ni(2) and one C(14) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ni(2) and one C(15) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Ni(1) and one C(15) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one C(7) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one C(16) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ni(2) and one C(16) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one C(17) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one C(17) atom. Linkers: 2 [O]C(=O)c1[c][c]cc(C(=O)c2ccc(C([O])=O)c(C([O])=O)c2)c1 ,2 [O]C(=O)c1ccc(C(=O)c2ccc(C([O])=O)c(C([O])=O)c2)cc1C([O])=O ,2 [CH]/C(=C\[C]C([O])=O)C(=O)c1ccc(C([O])=O)c(C([O])=O)c1 ,1 c1cnccn1. Metal clusters: 4 [Ni]. The MOF has largest included sphere 3.83 A, density 1.56 g/cm3, surface area 3886.38 m2/g, accessible volume 0.24 cm3/g