U2NiC12H12(NO6)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), and one O(7) atom. The U(1)-O(1) bond length is 2.53 Å. The U(1)-O(2) bond length is 2.46 Å. The U(1)-O(5) bond length is 2.32 Å. The U(1)-O(7) bond length is 2.31 Å. In the second U site, U(2) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(3), and one O(9) atom. The U(2)-O(10) bond length is 2.44 Å. The U(2)-O(11) bond length is 2.30 Å. The U(2)-O(3) bond length is 2.32 Å. The U(2)-O(9) bond length is 2.51 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in an octahedral geometry to two equivalent N(1), two equivalent O(4), and two equivalent O(6) atoms. Both Ni(1)-N(1) bond lengths are 2.08 Å. Both Ni(1)-O(4) bond lengths are 2.04 Å. Both Ni(1)-O(6) bond lengths are 2.01 Å. In the second Ni site, Ni(2) is bonded in an octahedral geometry to two equivalent N(2), two equivalent O(12), and two equivalent O(8) atoms. Both Ni(2)-N(2) bond lengths are 2.08 Å. Both Ni(2)-O(12) bond lengths are 2.02 Å. Both Ni(2)-O(8) bond lengths are 2.06 Å. There are twelve inequivalent C sites. In the first C site, C(1) is bonded in a 3-coordinate geometry to one C(2); one N(1); and two equivalent H(1,2) atoms. The C(1)-C(2) bond length is 1.51 Å. The C(1)-N(1) bond length is 1.48 Å. Both C(1)-H(1,2) bond lengths are 0.99 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(1), one O(1), and one O(2) atom. The C(2)-O(1) bond length is 1.27 Å. The C(2)-O(2) bond length is 1.26 Å. In the third C site, C(3) is bonded in a 3-coordinate geometry to one N(1) and two equivalent H(3,4) atoms. The C(3)-N(1) bond length is 1.47 Å. Both C(3)-H(3,4) bond lengths are 0.99 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(4) atom. The C(4)-O(3) bond length is 1.26 Å. The C(4)-O(4) bond length is 1.25 Å. In the fifth C site, C(5) is bonded in a 3-coordinate geometry to one C(6); one N(1); and two equivalent H(5,6) atoms. The C(5)-C(6) bond length is 1.52 Å. The C(5)-N(1) bond length is 1.49 Å. Both C(5)-H(5,6) bond lengths are 0.99 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one O(5), and one O(6) atom. The C(6)-O(5) bond length is 1.26 Å. The C(6)-O(6) bond length is 1.24 Å. In the seventh C site, C(7) is bonded in a 3-coordinate geometry to one N(2) and two equivalent H(7,8) atoms. The C(7)-N(2) bond length is 1.48 Å. Both C(7)-H(7,8) bond lengths are 0.99 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one O(7) and one O(8) atom. The C(8)-O(7) bond length is 1.28 Å. The C(8)-O(8) bond length is 1.24 Å. In the ninth C site, C(9) is bonded in a 3-coordinate geometry to one C(10); one N(2); and two equivalent H(9,10) atoms. The C(9)-C(10) bond length is 1.51 Å. The C(9)-N(2) bond length is 1.48 Å. Both C(9)-H(9,10) bond lengths are 0.99 Å. In the tenth C site, C(10) is bonded in a distorted trigonal planar geometry to one C(9), one O(10), and one O(9) atom. The C(10)-O(10) bond length is 1.26 Å. The C(10)-O(9) bond length is 1.26 Å. In the eleventh C site, C(11) is bonded in a 3-coordinate geometry to one C(12); one N(2); and two equivalent H(11,12) atoms. The C(11)-C(12) bond length is 1.51 Å. The C(11)-N(2) bond length is 1.50 Å. Both C(11)-H(11,12) bond lengths are 0.99 Å. In the twelfth C site, C(12) is bonded in a distorted trigonal planar geometry to one C(11), one O(11), and one O(12) atom. The C(12)-O(11) bond length is 1.26 Å. The C(12)-O(12) bond length is 1.25 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Ni(1), one C(1), one C(3), and one C(5) atom to form corner-sharing NNiC3 tetrahedra. In the second N site, N(2) is bonded to one Ni(2), one C(11), one C(7), and one C(9) atom to form corner-sharing NNiC3 tetrahedra. There are six inequivalent H sites. In the first H site, H(1,2) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(3,4) is bonded in a single-bond geometry to one C(3) atom. In the third H site, H(5,6) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(7,8) is bonded in a single-bond geometry to one C(7) atom. In the fifth H site, H(9,10) is bonded in a single-bond geometry to one C(9) atom. In the sixth H site, H(11,12) is bonded in a single-bond geometry to one C(11) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one U(1) and one C(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one U(1) and one C(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one U(2) and one C(4) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one Ni(1) and one C(4) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one U(1) and one C(6) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Ni(1) and one C(6) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one U(1) and one C(8) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Ni(2) and one C(8) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one U(2) and one C(10) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one U(2) and one C(10) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one U(2) and one C(12) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Ni(2) and one C(12) atom. Linkers: 8 [O]C(=O)CN(CC([O])=O)CC([O])=O. Metal clusters: 8 [U] ,4 [Ni]. The MOF has largest included sphere 5.86 A, density 1.63 g/cm3, surface area 2231.07 m2/g, accessible volume 0.41 cm3/g