NaEu2C56(N2O5)6 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent O(11) and two equivalent O(8) atoms. Both Na(1)-O(11) bond lengths are 2.85 Å. Both Na(1)-O(8) bond lengths are 2.39 Å. Eu(1) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(3), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. The Eu(1)-O(10) bond length is 2.51 Å. The Eu(1)-O(11) bond length is 2.43 Å. The Eu(1)-O(3) bond length is 2.42 Å. The Eu(1)-O(4) bond length is 2.45 Å. The Eu(1)-O(5) bond length is 2.49 Å. The Eu(1)-O(7) bond length is 2.38 Å. The Eu(1)-O(8) bond length is 2.56 Å. The Eu(1)-O(9) bond length is 2.47 Å. There are twenty-eight 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(3) atom. The C(1)-C(2) bond length is 1.47 Å. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(3) bond length is 1.21 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 1.37 Å. The C(2)-C(7) bond length is 1.38 Å. In the third C site, C(3) is bonded in a bent 120 degrees geometry to one C(2) and one C(4) atom. The C(3)-C(4) bond length is 1.42 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(6) atom. The C(4)-C(5) bond length is 1.43 Å. The C(4)-N(6) bond length is 1.43 Å. In the fifth C site, C(5) is bonded in a bent 120 degrees geometry to one C(4) and one C(6) atom. The C(5)-C(6) bond length is 1.41 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(5), one C(7), and one C(8) atom. The C(6)-C(7) bond length is 1.40 Å. The C(6)-C(8) bond length is 1.50 Å. In the seventh C site, C(7) is bonded in a bent 120 degrees geometry to one C(2) and one C(6) atom. In the eighth C site, C(8) is bonded in a bent 120 degrees geometry to one C(6), one O(4), and one O(5) atom. The C(8)-O(4) bond length is 1.24 Å. The C(8)-O(5) bond length is 1.25 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one N(1), one N(3), and one N(6) atom. The C(9)-N(1) bond length is 1.36 Å. The C(9)-N(3) bond length is 1.35 Å. The C(9)-N(6) bond length is 1.37 Å. In the tenth C site, C(10) is bonded in a distorted trigonal planar geometry to one N(2), one N(3), and one N(5) atom. The C(10)-N(2) bond length is 1.33 Å. The C(10)-N(3) bond length is 1.34 Å. The C(10)-N(5) bond length is 1.39 Å. In the eleventh C site, C(11) is bonded in a distorted trigonal planar geometry to one N(1), one N(2), and one N(4) atom. The C(11)-N(1) bond length is 1.32 Å. The C(11)-N(2) bond length is 1.34 Å. The C(11)-N(4) bond length is 1.40 Å. In the twelfth C site, C(12) is bonded in a distorted trigonal planar geometry to one C(13), one C(17), and one N(5) atom. The C(12)-C(13) bond length is 1.47 Å. The C(12)-C(17) bond length is 1.42 Å. The C(12)-N(5) bond length is 1.38 Å. In the thirteenth C site, C(13) is bonded in a bent 120 degrees geometry to one C(12) and one C(14) atom. The C(13)-C(14) bond length is 1.37 Å. In the fourteenth C site, C(14) is bonded in a trigonal planar geometry to one C(13), one C(15), and one C(19) atom. The C(14)-C(15) bond length is 1.45 Å. The C(14)-C(19) bond length is 1.44 Å. In the fifteenth C site, C(15) is bonded in a bent 120 degrees geometry to one C(14) and one C(16) atom. The C(15)-C(16) bond length is 1.37 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(18) atom. The C(16)-C(17) bond length is 1.39 Å. The C(16)-C(18) bond length is 1.48 Å. In the seventeenth C site, C(17) is bonded in a bent 120 degrees geometry to one C(12) and one C(16) atom. In the eighteenth C site, C(18) is bonded in a distorted bent 120 degrees geometry to one C(16), one O(6), and one O(7) atom. The C(18)-O(6) bond length is 1.21 Å. The C(18)-O(7) bond length is 1.24 Å. In the nineteenth C site, C(19) is bonded in a bent 120 degrees geometry to one C(14), one O(8), and one O(9) atom. The C(19)-O(8) bond length is 1.25 Å. The C(19)-O(9) bond length is 1.26 Å. In the twentieth C site, C(20) is bonded in a distorted trigonal planar geometry to one C(21), one C(25), and one N(4) atom. The C(20)-C(21) bond length is 1.38 Å. The C(20)-C(25) bond length is 1.33 Å. The C(20)-N(4) bond length is 1.40 Å. In the twenty-first C site, C(21) is bonded in a bent 120 degrees geometry to one C(20) and one C(22) atom. The C(21)-C(22) bond length is 1.38 Å. In the twenty-second C site, C(22) is bonded in a trigonal planar geometry to one C(21), one C(23), and one C(27) atom. The C(22)-C(23) bond length is 1.37 Å. The C(22)-C(27) bond length is 1.52 Å. In the twenty-third C site, C(23) is bonded in a bent 120 degrees geometry to one C(22) and one C(24) atom. The C(23)-C(24) bond length is 1.30 Å. In the twenty-fourth C site, C(24) is bonded in a 4-coordinate geometry to one C(23), one C(25), one C(26), and one C(28) atom. The C(24)-C(25) bond length is 1.46 Å. The C(24)-C(26) bond length is 1.47 Å. The C(24)-C(28) bond length is 1.51 Å. In the twenty-fifth C site, C(25) is bonded in a bent 120 degrees geometry to one C(20) and one C(24) atom. In the twenty-sixth C site, C(26) is bonded in a 6-coordinate geometry to one C(24), one C(28), one O(12), one O(14), one O(15), and one O(2) atom. The C(26)-C(28) bond length is 1.33 Å. The C(26)-O(12) bond length is 1.34 Å. The C(26)-O(14) bond length is 1.32 Å. The C(26)-O(15) bond length is 1.45 Å. The C(26)-O(2) bond length is 1.45 Å. In the twenty-seventh C site, C(27) is bonded in a bent 120 degrees geometry to one C(22), one O(10), and one O(11) atom. The C(27)-O(10) bond length is 1.25 Å. The C(27)-O(11) bond length is 1.21 Å. In the twenty-eighth C site, C(28) is bonded in a 3-coordinate geometry to one C(24), one C(26), and one O(15) atom. The C(28)-O(15) bond length is 1.30 Å. There are six inequivalent N sites. In the first N site, N(1) is bonded in a water-like geometry to one C(11) and one C(9) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one C(10) and one C(11) atom. In the third N site, N(3) is bonded in a water-like geometry to one C(10) and one C(9) atom. In the fourth N site, N(4) is bonded in a bent 120 degrees geometry to one C(11) and one C(20) atom. In the fifth N site, N(5) is bonded in a bent 120 degrees geometry to one C(10) and one C(12) atom. In the sixth N site, N(6) is bonded in a bent 120 degrees geometry to one C(4) and one C(9) atom. There are fifteen inequivalent O sites. In the first O site, O(2) is bonded in a 2-coordinate geometry to one C(26) and one O(14) atom. The O(2)-O(14) bond length is 1.02 Å. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Eu(1) and one C(1) atom. In the third O site, O(4) is bonded in a distorted L-shaped geometry to one Eu(1) and one C(8) atom. In the fourth O site, O(5) is bonded in a distorted L-shaped geometry to one Eu(1) and one C(8) atom. In the fifth O site, O(7) is bonded in a bent 150 degrees geometry to one Eu(1) and one C(18) atom. In the sixth O site, O(8) is bonded in a 3-coordinate geometry to one Na(1), one Eu(1), and one C(19) atom. In the seventh O site, O(9) is bonded in a distorted L-shaped geometry to one Eu(1) and one C(19) atom. In the eighth O site, O(10) is bonded in a distorted L-shaped geometry to one Eu(1) and one C(27) atom. In the ninth O site, O(6) is bonded in a single-bond geometry to one C(18) atom. In the tenth O site, O(12) is bonded in a single-bond geometry to one C(26) atom. In the eleventh O site, O(13) is bonded in a single-bond geometry to one O(14) atom. The O(13)-O(14) bond length is 0.91 Å. In the twelfth O site, O(14) is bonded in a single-bond geometry to one C(26), one O(13), and one O(2) atom. In the thirteenth O site, O(15) is bonded in a distorted single-bond geometry to one C(26) and one C(28) atom. In the fourteenth O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Eu(1), and one C(27) atom. In the fifteenth O site, O(1) is bonded in a single-bond geometry to one C(1) atom. Linkers: 2 [O]C(=O)C1=[C][C@]2([C]/C(=N\[C]3=[N]=[C](=[N]=[C](=[N]=3)[N]C3=[C]C(=[C]C(=[C]3)C(=O)[O])C(=O)[O])[N]C3=[C]C(=[C]C(=[C]3)C(=O)[O])C(=O)[O])/[C]1)[C@]13[C@]2(OOO1)OO3 ,2 [O]OO[C@]1([C]OO1)C1=[C]C(=[C]C(=[C]1)[N][C]1=[N]=[C](=[N]=[C](=[N]=1)[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])C(=O)[O] ,1 [O]OO[C@@]1([C]OO1)C1=[C]C(=[C]C(=[C]1)[N][C]1=[N]=[C](=[N]=[C](=[N]=1)[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])C(=O)[O] ,2 [O]OO[C@@]1([C]OO1)C1=[C]C(=[C]C(=[C]1)C(=O)[O])[N][C]1=[N]=[C](=[N]=[C](=[N]=1)[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O] ,1 [O]C(=O)C1=[C][C@]2([C]=C([C]1)[N][C]1=[N]=[C](=[N]=[C](=[N]=1)[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])[N]C1=[C]C(=[C]C(=[C]1)C(=O)[O])C(=O)[O])[C@]13[C@]2(OOO1)OO3. Metal clusters: 4 O=[C]O[Eu]1(O[C]=O)(O[C]=O)(O[C]=O)O[C]O1.O=[C]O[Eu]1(O[C]O[Na])(O[C]=O)(O[C]=O)O[C]O1. RCSR code: ant. The MOF has largest included sphere 12.75 A, density 0.62 g/cm3, surface area 3680.64 m2/g, accessible volume 1.25 cm3/g