GdC21H6(NO3)6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 7-coordinate geometry to one O(11), one O(13), one O(18), one O(2), one O(28), one O(35), and one O(36) atom. The Gd(1)-O(11) bond length is 2.72 Å. The Gd(1)-O(13) bond length is 2.40 Å. The Gd(1)-O(18) bond length is 2.39 Å. The Gd(1)-O(2) bond length is 2.36 Å. The Gd(1)-O(28) bond length is 2.50 Å. The Gd(1)-O(35) bond length is 2.41 Å. The Gd(1)-O(36) bond length is 2.44 Å. In the second Gd site, Gd(2) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(12), one O(19), one O(2), one O(29), and one O(30) atom. The Gd(2)-O(1) bond length is 2.50 Å. The Gd(2)-O(11) bond length is 2.35 Å. The Gd(2)-O(12) bond length is 2.41 Å. The Gd(2)-O(19) bond length is 2.41 Å. The Gd(2)-O(2) bond length is 2.63 Å. The Gd(2)-O(29) bond length is 2.48 Å. The Gd(2)-O(30) bond length is 2.49 Å. There are forty-two 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 1.52 Å. The C(1)-O(1) bond length is 1.24 Å. The C(1)-O(2) bond length is 1.27 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(7) atom. The C(2)-C(3) bond length is 1.38 Å. The C(2)-C(7) bond length is 1.38 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.38 Å. The C(3)-H(1) bond length is 0.93 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 N(1) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-N(1) bond length is 1.47 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one C(8) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-C(8) bond length is 1.50 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one C(7), and one N(2) atom. The C(6)-C(7) bond length is 1.38 Å. The C(6)-N(2) bond length is 1.47 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(2), one C(6), and one H(2) atom. The C(7)-H(2) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(13), one C(5), and one C(9) atom. The C(8)-C(13) bond length is 1.40 Å. The C(8)-C(9) bond length is 1.40 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(10), one C(8), and one N(3) atom. The C(9)-C(10) bond length is 1.38 Å. The C(9)-N(3) bond length is 1.47 Å. In the tenth C site, C(10) is bonded in a distorted trigonal planar geometry to one C(11), one C(9), and one H(3) atom. The C(10)-C(11) bond length is 1.38 Å. The C(10)-H(3) 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(14) atom. The C(11)-C(12) bond length is 1.38 Å. The C(11)-C(14) bond length is 1.50 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(11), one C(13), and one H(4) atom. The C(12)-C(13) bond length is 1.39 Å. The C(12)-H(4) bond length is 0.93 Å. In the thirteenth C site, C(13) is bonded in a distorted trigonal planar geometry to one C(12), one C(8), and one N(4) atom. The C(13)-N(4) bond length is 1.47 Å. In the fourteenth C site, C(14) is bonded in a bent 120 degrees geometry to one C(11), one O(11), and one O(35) atom. The C(14)-O(11) bond length is 1.26 Å. The C(14)-O(35) bond length is 1.25 Å. In the fifteenth C site, C(15) is bonded in a distorted bent 120 degrees geometry to one C(16), one O(12), and one O(13) atom. The C(15)-C(16) bond length is 1.52 Å. The C(15)-O(12) bond length is 1.25 Å. The C(15)-O(13) bond length is 1.25 Å. In the sixteenth C site, C(16) is bonded in a trigonal planar geometry to one C(15), one C(17), and one C(21) atom. The C(16)-C(17) bond length is 1.38 Å. The C(16)-C(21) bond length is 1.38 Å. In the seventeenth C site, C(17) is bonded in a distorted single-bond geometry to one C(16), one C(18), and one H(5) atom. The C(17)-C(18) bond length is 1.39 Å. The C(17)-H(5) bond length is 0.93 Å. In the eighteenth C site, C(18) is bonded in a distorted trigonal planar geometry to one C(17), one C(19), and one N(5) atom. The C(18)-C(19) bond length is 1.39 Å. The C(18)-N(5) bond length is 1.47 Å. In the nineteenth C site, C(19) is bonded in a trigonal planar geometry to one C(18), one C(20), and one C(40) atom. The C(19)-C(20) bond length is 1.40 Å. The C(19)-C(40) bond length is 1.50 Å. In the twentieth C site, C(20) is bonded in a distorted trigonal planar geometry to one C(19), one C(21), and one N(6) atom. The C(20)-C(21) bond length is 1.37 Å. The C(20)-N(6) bond length is 1.47 Å. In the twenty-first C site, C(21) is bonded in a distorted trigonal planar geometry to one C(16), one C(20), and one H(6) atom. The C(21)-H(6) bond length is 0.93 Å. In the twenty-second C site, C(22) is bonded in a distorted bent 120 degrees geometry to one C(23), one O(18), and one O(19) atom. The C(22)-C(23) bond length is 1.51 Å. The C(22)-O(18) bond length is 1.25 Å. The C(22)-O(19) bond length is 1.25 Å. In the twenty-third C site, C(23) is bonded in a trigonal planar geometry to one C(22), one C(24), and one C(28) atom. The C(23)-C(24) bond length is 1.38 Å. The C(23)-C(28) bond length is 1.39 Å. In the twenty-fourth C site, C(24) is bonded in a distorted single-bond geometry to one C(23), one C(25), and one H(7) atom. The C(24)-C(25) bond length is 1.39 Å. The C(24)-H(7) bond length is 0.93 Å. In the twenty-fifth C site, C(25) is bonded in a distorted trigonal planar geometry to one C(24), one C(26), and one N(7) atom. The C(25)-C(26) bond length is 1.38 Å. The C(25)-N(7) bond length is 1.48 Å. In the twenty-sixth C site, C(26) is bonded in a trigonal planar geometry to one C(25), one C(27), and one C(29) atom. The C(26)-C(27) bond length is 1.41 Å. The C(26)-C(29) bond length is 1.50 Å. In the twenty-seventh C site, C(27) is bonded in a distorted trigonal planar geometry to one C(26), one C(28), and one N(8) atom. The C(27)-C(28) bond length is 1.38 Å. The C(27)-N(8) bond length is 1.47 Å. In the twenty-eighth C site, C(28) is bonded in a distorted trigonal planar geometry to one C(23), one C(27), and one H(8) atom. The C(28)-H(8) bond length is 0.93 Å. In the twenty-ninth C site, C(29) is bonded in a trigonal planar geometry to one C(26), one C(30), and one C(34) atom. The C(29)-C(30) bond length is 1.39 Å. The C(29)-C(34) bond length is 1.40 Å. In the thirtieth C site, C(30) is bonded in a distorted trigonal planar geometry to one C(29), one C(31), and one N(9) atom. The C(30)-C(31) bond length is 1.38 Å. The C(30)-N(9) bond length is 1.48 Å. In the thirty-first C site, C(31) is bonded in a distorted single-bond geometry to one C(30), one C(32), and one H(9) atom. The C(31)-C(32) bond length is 1.39 Å. The C(31)-H(9) bond length is 0.93 Å. In the thirty-second C site, C(32) is bonded in a trigonal planar geometry to one C(31), one C(33), and one C(35) atom. The C(32)-C(33) bond length is 1.39 Å. The C(32)-C(35) bond length is 1.50 Å. In the thirty-third C site, C(33) is bonded in a distorted trigonal planar geometry to one C(32), one C(34), and one H(10) atom. The C(33)-C(34) bond length is 1.38 Å. The C(33)-H(10) bond length is 0.93 Å. In the thirty-fourth C site, C(34) is bonded in a distorted trigonal planar geometry to one C(29), one C(33), and one N(10) atom. The C(34)-N(10) bond length is 1.47 Å. In the thirty-fifth C site, C(35) is bonded in a distorted bent 120 degrees geometry to one C(32), one O(28), and one O(36) atom. The C(35)-O(28) bond length is 1.25 Å. The C(35)-O(36) bond length is 1.26 Å. In the thirty-sixth C site, C(36) is bonded in a distorted bent 120 degrees geometry to one C(37), one O(29), and one O(30) atom. The C(36)-C(37) bond length is 1.51 Å. The C(36)-O(29) bond length is 1.25 Å. The C(36)-O(30) bond length is 1.26 Å. In the thirty-seventh C site, C(37) is bonded in a trigonal planar geometry to one C(36), one C(38), and one C(42) atom. The C(37)-C(38) bond length is 1.38 Å. The C(37)-C(42) bond length is 1.38 Å. In the thirty-eighth C site, C(38) is bonded in a distorted trigonal planar geometry to one C(37), one C(39), and one H(11) atom. The C(38)-C(39) bond length is 1.38 Å. The C(38)-H(11) bond length is 0.93 Å. In the thirty-ninth C site, C(39) is bonded in a distorted trigonal planar geometry to one C(38), one C(40), and one N(12) atom. The C(39)-C(40) bond length is 1.41 Å. The C(39)-N(12) bond length is 1.46 Å. In the fortieth C site, C(40) is bonded in a trigonal planar geometry to one C(19), one C(39), and one C(41) atom. The C(40)-C(41) bond length is 1.39 Å. In the forty-first C site, C(41) is bonded in a distorted trigonal planar geometry to one C(40), one C(42), and one N(11) atom. The C(41)-C(42) bond length is 1.39 Å. The C(41)-N(11) bond length is 1.49 Å. In the forty-second C site, C(42) is bonded in a distorted single-bond geometry to one C(37), one C(41), and one H(12) atom. The C(42)-H(12) bond length is 0.93 Å. There are twelve inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one C(4), one O(3), and one O(4) atom. The N(1)-O(3) bond length is 1.21 Å. The N(1)-O(4) bond length is 1.22 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one C(6), one O(5), and one O(6) atom. The N(2)-O(5) bond length is 1.21 Å. The N(2)-O(6) bond length is 1.20 Å. In the third N site, N(3) is bonded in a trigonal planar geometry to one C(9), one O(10), and one O(9) atom. The N(3)-O(10) bond length is 1.20 Å. The N(3)-O(9) bond length is 1.21 Å. In the fourth N site, N(4) is bonded in a trigonal planar geometry to one C(13), one O(7), and one O(8) atom. The N(4)-O(7) bond length is 1.21 Å. The N(4)-O(8) bond length is 1.22 Å. In the fifth N site, N(5) is bonded in a trigonal planar geometry to one C(18), one O(16), and one O(17) atom. The N(5)-O(16) bond length is 1.22 Å. The N(5)-O(17) bond length is 1.22 Å. In the sixth N site, N(6) is bonded in a trigonal planar geometry to one C(20), one O(14), and one O(15) atom. The N(6)-O(14) bond length is 1.18 Å. The N(6)-O(15) bond length is 1.21 Å. In the seventh N site, N(7) is bonded in a trigonal planar geometry to one C(25), one O(20), and one O(21) atom. The N(7)-O(20) bond length is 1.22 Å. The N(7)-O(21) bond length is 1.21 Å. In the eighth N site, N(8) is bonded in a trigonal planar geometry to one C(27), one O(22), and one O(23) atom. The N(8)-O(22) bond length is 1.23 Å. The N(8)-O(23) bond length is 1.23 Å. In the ninth N site, N(9) is bonded in a trigonal planar geometry to one C(30), one O(24), and one O(25) atom. The N(9)-O(24) bond length is 1.22 Å. The N(9)-O(25) bond length is 1.22 Å. In the tenth N site, N(10) is bonded in a trigonal planar geometry to one C(34), one O(26), and one O(27) atom. The N(10)-O(26) bond length is 1.21 Å. The N(10)-O(27) bond length is 1.21 Å. In the eleventh N site, N(11) is bonded in a trigonal planar geometry to one C(41), one O(33), and one O(34) atom. The N(11)-O(33) bond length is 1.22 Å. The N(11)-O(34) bond length is 1.21 Å. In the twelfth N site, N(12) is bonded in a trigonal planar geometry to one C(39), one O(31), and one O(32) atom. The N(12)-O(31) bond length is 1.20 Å. The N(12)-O(32) bond length is 1.19 Å. There are twelve 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(7) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(10) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(12) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(17) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(21) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(24) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(28) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(31) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(33) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one C(38) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one C(42) atom. There are thirty-six inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Gd(2) and one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Gd(1), one Gd(2), and one C(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one N(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one N(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one N(2) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one N(4) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one N(4) atom. In the ninth O site, O(9) is bonded in a single-bond geometry to one N(3) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one N(3) atom. In the eleventh O site, O(11) is bonded in a 1-coordinate geometry to one Gd(1), one Gd(2), and one C(14) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Gd(2) and one C(15) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one C(15) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one N(6) atom. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one N(6) atom. In the sixteenth O site, O(16) is bonded in a single-bond geometry to one N(5) atom. In the seventeenth O site, O(17) is bonded in a single-bond geometry to one N(5) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one Gd(1) and one C(22) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one Gd(2) and one C(22) atom. In the twentieth O site, O(20) is bonded in a single-bond geometry to one N(7) atom. In the twenty-first O site, O(21) is bonded in a single-bond geometry to one N(7) atom. In the twenty-second O site, O(22) is bonded in a single-bond geometry to one N(8) atom. In the twenty-third O site, O(23) is bonded in a single-bond geometry to one N(8) atom. In the twenty-fourth O site, O(24) is bonded in a single-bond geometry to one N(9) atom. In the twenty-fifth O site, O(25) is bonded in a single-bond geometry to one N(9) atom. In the twenty-sixth O site, O(26) is bonded in a single-bond geometry to one N(10) atom. In the twenty-seventh O site, O(27) is bonded in a single-bond geometry to one N(10) atom. In the twenty-eighth O site, O(28) is bonded in a single-bond geometry to one Gd(1) and one C(35) atom. In the twenty-ninth O site, O(29) is bonded in a distorted single-bond geometry to one Gd(2) and one C(36) atom. In the thirtieth O site, O(30) is bonded in a distorted single-bond geometry to one Gd(2) and one C(36) atom. In the thirty-first O site, O(31) is bonded in a single-bond geometry to one N(12) atom. In the thirty-second O site, O(32) is bonded in a single-bond geometry to one N(12) atom. In the thirty-third O site, O(33) is bonded in a single-bond geometry to one N(11) atom. In the thirty-fourth O site, O(34) is bonded in a single-bond geometry to one N(11) atom. In the thirty-fifth O site, O(35) is bonded in a distorted water-like geometry to one Gd(1) and one C(14) atom. In the thirty-sixth O site, O(36) is bonded in a distorted L-shaped geometry to one Gd(1) and one C(35) atom. Linkers: 12 [O]C(=O)c1cc([N+](=O)[O-])c(-c2c([N+](=O)[O-])cc(C([O])=O)cc2[N+](=O)[O-])c([N+](=O)[O-])c1. Metal clusters: 4 [C]1O[Gd]234(O1)O[C]O[Gd]1(O[C]O1)(O[C]O2)(O[C]O3)O[C]O4. RCSR code: pcu. The MOF has largest included sphere 6.79 A, density 1.16 g/cm3, surface area 3571.82 m2/g, accessible volume 0.48 cm3/g