YbNdH3(C5O4)3 crystallizes in the triclinic P1 space group. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 7-coordinate geometry to one O(1), one O(13), one O(14), one O(17), one O(21), one O(3), and one O(6) atom. The Yb(1)-O(1) bond length is 2.44 Å. The Yb(1)-O(13) bond length is 2.48 Å. The Yb(1)-O(14) bond length is 2.66 Å. The Yb(1)-O(17) bond length is 2.41 Å. The Yb(1)-O(21) bond length is 2.42 Å. The Yb(1)-O(3) bond length is 2.44 Å. The Yb(1)-O(6) bond length is 2.34 Å. In the second Yb site, Yb(2) is bonded in a 6-coordinate geometry to one O(10), one O(15), one O(16), one O(24), one O(7), and one O(8) atom. The Yb(2)-O(10) bond length is 2.24 Å. The Yb(2)-O(15) bond length is 2.49 Å. The Yb(2)-O(16) bond length is 2.39 Å. The Yb(2)-O(24) bond length is 2.20 Å. The Yb(2)-O(7) bond length is 2.35 Å. The Yb(2)-O(8) bond length is 2.47 Å. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 7-coordinate geometry to one O(1), one O(13), one O(15), one O(18), one O(2), one O(5), and one O(9) atom. The Nd(1)-O(1) bond length is 2.48 Å. The Nd(1)-O(13) bond length is 2.44 Å. The Nd(1)-O(15) bond length is 2.44 Å. The Nd(1)-O(18) bond length is 2.34 Å. The Nd(1)-O(2) bond length is 2.66 Å. The Nd(1)-O(5) bond length is 2.41 Å. The Nd(1)-O(9) bond length is 2.42 Å. In the second Nd site, Nd(2) is bonded in a 6-coordinate geometry to one O(12), one O(19), one O(20), one O(22), one O(3), and one O(4) atom. The Nd(2)-O(12) bond length is 2.20 Å. The Nd(2)-O(19) bond length is 2.35 Å. The Nd(2)-O(20) bond length is 2.47 Å. The Nd(2)-O(22) bond length is 2.24 Å. The Nd(2)-O(3) bond length is 2.49 Å. The Nd(2)-O(4) bond length is 2.39 Å. There are twenty-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 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 1.29 Å. The C(1)-O(2) bond length is 1.24 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(5,20) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(5,20) bond length is 1.40 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(5,20) atom. The C(3)-C(4) bond length is 1.51 Å. The C(3)-C(5,20) bond length is 1.38 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(3), and one O(4) atom. The C(4)-O(3) bond length is 1.28 Å. The C(4)-O(4) bond length is 1.25 Å. In the fifth C site, C(5,20) is bonded in a distorted single-bond geometry to one C(18); one C(2); and one H(1,4) atom. The C(5,20)-C(18) bond length is 1.38 Å. The C(5,20)-H(1,4) bond length is 0.93 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(5), and one O(6) atom. The C(6)-C(7) bond length is 1.52 Å. The C(6)-O(5) bond length is 1.24 Å. The C(6)-O(6) bond length is 1.27 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(10,25); one C(6); and one C(8) atom. The C(7)-C(10,25) bond length is 1.40 Å. The C(7)-C(8) bond length is 1.39 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(10,25); one C(7); and one C(9) atom. The C(8)-C(10,25) bond length is 1.38 Å. The C(8)-C(9) bond length is 1.50 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(7), and one O(8) atom. The C(9)-O(7) bond length is 1.28 Å. The C(9)-O(8) bond length is 1.26 Å. In the tenth C site, C(10,25) is bonded in a distorted single-bond geometry to one C(23); one C(7); and one H(2,5) atom. The C(10,25)-C(23) bond length is 1.38 Å. The C(10,25)-H(2,5) bond length is 0.93 Å. In the eleventh C site, C(11) is bonded in a distorted bent 120 degrees geometry to one C(12), one O(10), and one O(9) atom. The C(11)-C(12) bond length is 1.50 Å. The C(11)-O(10) bond length is 1.25 Å. The C(11)-O(9) bond length is 1.26 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(15,30) atom. The C(12)-C(13) bond length is 1.40 Å. The C(12)-C(15,30) bond length is 1.39 Å. In the thirteenth C site, C(13) is bonded in a trigonal planar geometry to one C(12); one C(14); and one C(15,30) atom. The C(13)-C(14) bond length is 1.51 Å. The C(13)-C(15,30) bond length is 1.39 Å. In the fourteenth C site, C(14) is bonded in a distorted bent 120 degrees geometry to one C(13), one O(11), and one O(12) atom. The C(14)-O(11) bond length is 1.24 Å. The C(14)-O(12) bond length is 1.28 Å. In the fifteenth C site, C(15,30) is bonded in a distorted single-bond geometry to one C(12); one C(28); and one H(3,6) atom. The C(15,30)-C(28) bond length is 1.39 Å. The C(15,30)-H(3,6) bond length is 0.93 Å. In the sixteenth C site, C(16) is bonded in a distorted bent 120 degrees geometry to one C(17), one O(13), and one O(14) atom. The C(16)-C(17) bond length is 1.50 Å. The C(16)-O(13) bond length is 1.29 Å. The C(16)-O(14) bond length is 1.24 Å. In the seventeenth C site, C(17) is bonded in a trigonal planar geometry to one C(16); one C(18); and one C(5,20) atom. The C(17)-C(18) bond length is 1.40 Å. The C(17)-C(5,20) bond length is 1.40 Å. In the eighteenth C site, C(18) is bonded in a trigonal planar geometry to one C(17); one C(19); and one C(5,20) atom. The C(18)-C(19) bond length is 1.51 Å. In the nineteenth C site, C(19) is bonded in a distorted bent 120 degrees geometry to one C(18), one O(15), and one O(16) atom. The C(19)-O(15) bond length is 1.28 Å. The C(19)-O(16) bond length is 1.25 Å. In the twentieth C site, C(21) is bonded in a distorted bent 120 degrees geometry to one C(22), one O(17), and one O(18) atom. The C(21)-C(22) bond length is 1.52 Å. The C(21)-O(17) bond length is 1.24 Å. The C(21)-O(18) bond length is 1.27 Å. In the twenty-first C site, C(22) is bonded in a trigonal planar geometry to one C(10,25); one C(21); and one C(23) atom. The C(22)-C(10,25) bond length is 1.40 Å. The C(22)-C(23) bond length is 1.39 Å. In the twenty-second C site, C(23) is bonded in a trigonal planar geometry to one C(10,25); one C(22); and one C(24) atom. The C(23)-C(24) bond length is 1.50 Å. In the twenty-third C site, C(24) is bonded in a distorted bent 120 degrees geometry to one C(23), one O(19), and one O(20) atom. The C(24)-O(19) bond length is 1.28 Å. The C(24)-O(20) bond length is 1.26 Å. In the twenty-fourth C site, C(26) is bonded in a distorted bent 120 degrees geometry to one C(27), one O(21), and one O(22) atom. The C(26)-C(27) bond length is 1.50 Å. The C(26)-O(21) bond length is 1.26 Å. The C(26)-O(22) bond length is 1.25 Å. In the twenty-fifth C site, C(27) is bonded in a trigonal planar geometry to one C(15,30); one C(26); and one C(28) atom. The C(27)-C(15,30) bond length is 1.39 Å. The C(27)-C(28) bond length is 1.40 Å. In the twenty-sixth C site, C(28) is bonded in a trigonal planar geometry to one C(15,30); one C(27); and one C(29) atom. The C(28)-C(29) bond length is 1.51 Å. In the twenty-seventh C site, C(29) is bonded in a distorted bent 120 degrees geometry to one C(28), one O(23), and one O(24) atom. The C(29)-O(23) bond length is 1.24 Å. The C(29)-O(24) bond length is 1.28 Å. There are three inequivalent H sites. In the first H site, H(1,4) is bonded in a single-bond geometry to one C(5,20) atom. In the second H site, H(2,5) is bonded in a single-bond geometry to one C(10,25) atom. In the third H site, H(3,6) is bonded in a single-bond geometry to one C(15,30) atom. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Yb(1), one Nd(1), and one C(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Nd(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Yb(1), one Nd(2), and one C(4) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Nd(2) and one C(4) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Nd(1) and one C(6) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Yb(1) and one C(6) atom. In the seventh O site, O(7) is bonded in a distorted L-shaped geometry to one Yb(2) and one C(9) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one Yb(2) and one C(9) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Nd(1) and one C(11) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Yb(2) and one C(11) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one C(14) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Nd(2) and one C(14) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Yb(1), one Nd(1), and one C(16) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one Yb(1) and one C(16) atom. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one Yb(2), one Nd(1), and one C(19) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one Yb(2) and one C(19) atom. In the seventeenth O site, O(17) is bonded in a distorted single-bond geometry to one Yb(1) and one C(21) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one Nd(1) and one C(21) atom. In the nineteenth O site, O(19) is bonded in a distorted L-shaped geometry to one Nd(2) and one C(24) atom. In the twentieth O site, O(20) is bonded in a single-bond geometry to one Nd(2) and one C(24) atom. In the twenty-first O site, O(21) is bonded in a distorted single-bond geometry to one Yb(1) and one C(26) atom. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to one Nd(2) and one C(26) atom. In the twenty-third O site, O(23) is bonded in a single-bond geometry to one C(29) atom. In the twenty-fourth O site, O(24) is bonded in a distorted bent 150 degrees geometry to one Yb(2) and one C(29) atom. Linkers: 3 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 1 O=[C]O[Nd]12(O[C]O1)O[C]O[Yb]1(O[C]=O)(O[C]O2)O[C]O[Nd]2(O[C]=O)(O[C]O1)O[C]O[Yb]1(O[C]=O)(O[C]O2)O[C]O1. The MOF has largest included sphere 4.61 A, density 2.16 g/cm3, surface area 2298.92 m2/g, accessible volume 0.14 cm3/g