(EuC7N2H6O7)2H2O crystallizes in the monoclinic P2_1/c space group. The structure consists of four water molecules inside a EuC7N2H6O7 framework. In the EuC7N2H6O7 framework, there are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 9-coordinate geometry to one N(1), one N(3), one O(1), one O(10), one O(11), one O(12), one O(5), one O(8), and one O(9) atom. The Eu(1)-N(1) bond length is 2.59 Å. The Eu(1)-N(3) bond length is 2.67 Å. The Eu(1)-O(1) bond length is 2.46 Å. The Eu(1)-O(10) bond length is 2.39 Å. The Eu(1)-O(11) bond length is 2.55 Å. The Eu(1)-O(12) bond length is 2.44 Å. The Eu(1)-O(5) bond length is 2.42 Å. The Eu(1)-O(8) bond length is 2.44 Å. The Eu(1)-O(9) bond length is 2.44 Å. In the second Eu site, Eu(2) is bonded in a 7-coordinate geometry to one O(13), one O(14), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. The Eu(2)-O(13) bond length is 2.42 Å. The Eu(2)-O(14) bond length is 2.45 Å. The Eu(2)-O(2) bond length is 2.33 Å. The Eu(2)-O(3) bond length is 2.36 Å. The Eu(2)-O(4) bond length is 2.31 Å. The Eu(2)-O(6) bond length is 2.39 Å. The Eu(2)-O(7) bond length is 2.36 Å. There are fourteen inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one N(1) atom. The C(1)-C(2) bond length is 1.39 Å. The C(1)-C(4) bond length is 1.48 Å. The C(1)-N(1) bond length is 1.38 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one N(2) atom. The C(2)-C(5) bond length is 1.48 Å. The C(2)-N(2) bond length is 1.38 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(6), one N(1), and one N(2) atom. The C(3)-C(6) bond length is 1.48 Å. The C(3)-N(1) bond length is 1.34 Å. The C(3)-N(2) bond length is 1.36 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(4)-O(1) bond length is 1.28 Å. The C(4)-O(2) bond length is 1.27 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(5)-O(3) bond length is 1.26 Å. The C(5)-O(4) bond length is 1.27 Å. In the sixth C site, C(6) is bonded in a distorted trigonal non-coplanar geometry to one C(3), one H(10), one H(11), and one H(9) atom. The C(6)-H(10) bond length is 1.10 Å. The C(6)-H(11) bond length is 1.09 Å. The C(6)-H(9) bond length is 1.10 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(10), one C(8), and one N(4) atom. The C(7)-C(10) bond length is 1.48 Å. The C(7)-C(8) bond length is 1.39 Å. The C(7)-N(4) bond length is 1.38 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(11), one C(7), and one N(3) atom. The C(8)-C(11) bond length is 1.48 Å. The C(8)-N(3) bond length is 1.38 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(12), one N(3), and one N(4) atom. The C(9)-C(12) bond length is 1.48 Å. The C(9)-N(3) bond length is 1.34 Å. The C(9)-N(4) bond length is 1.36 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(5), and one O(6) atom. The C(10)-O(5) bond length is 1.26 Å. The C(10)-O(6) bond length is 1.28 Å. In the eleventh C site, C(11) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(7), and one O(8) atom. The C(11)-O(7) bond length is 1.28 Å. The C(11)-O(8) bond length is 1.26 Å. In the twelfth C site, C(12) is bonded in a distorted trigonal non-coplanar geometry to one C(9), one H(12), one H(13), and one H(14) atom. The C(12)-H(12) bond length is 1.10 Å. The C(12)-H(13) bond length is 1.10 Å. The C(12)-H(14) bond length is 1.10 Å. In the thirteenth C site, C(13) is bonded in a distorted bent 120 degrees geometry to one O(10) and one O(9) atom. The C(13)-O(10) bond length is 1.26 Å. The C(13)-O(9) bond length is 1.26 Å. In the fourteenth C site, C(14) is bonded in a distorted bent 120 degrees geometry to one O(11) and one O(12) atom. The C(14)-O(11) bond length is 1.28 Å. The C(14)-O(12) bond length is 1.26 Å. There are four inequivalent N sites. In the first N site, N(3) is bonded in a distorted water-like geometry to one Eu(1), one C(8), and one C(9) atom. In the second N site, N(4) is bonded in a trigonal planar geometry to one C(7), one C(9), and one H(8) atom. The N(4)-H(8) bond length is 1.02 Å. In the third N site, N(1) is bonded in a distorted water-like geometry to one Eu(1), one C(1), and one C(3) atom. In the fourth N site, N(2) is bonded in a distorted trigonal planar geometry to one C(2), one C(3), and one H(7) atom. The N(2)-H(7) bond length is 1.03 Å. There are twelve inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) and one O(13) atom. The H(1)-O(1) bond length is 1.70 Å. The H(1)-O(13) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(13) atom. The H(2)-O(13) bond length is 0.98 Å. In the third H site, H(3) is bonded in a distorted linear geometry to one O(11) and one O(14) atom. The H(3)-O(11) bond length is 1.60 Å. The H(3)-O(14) bond length is 1.02 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(14) atom. The H(4)-O(14) bond length is 0.97 Å. In the fifth H site, H(7) is bonded in a single-bond geometry to one N(2) atom. In the sixth H site, H(8) is bonded in a single-bond geometry to one N(4) atom. In the seventh H site, H(9) is bonded in a single-bond geometry to one C(6) atom. In the eighth H site, H(10) is bonded in a single-bond geometry to one C(6) atom. In the ninth H site, H(11) is bonded in a single-bond geometry to one C(6) atom. In the tenth H site, H(12) is bonded in a single-bond geometry to one C(12) atom. In the eleventh H site, H(13) is bonded in a single-bond geometry to one C(12) atom. In the twelfth H site, H(14) is bonded in a single-bond geometry to one C(12) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Eu(1), one C(4), and one H(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Eu(2) and one C(4) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Eu(2) and one C(5) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Eu(2) and one C(5) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Eu(1) and one C(10) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Eu(2) and one C(10) atom. In the seventh O site, O(7) is bonded in a 1-coordinate geometry to one Eu(2) and one C(11) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Eu(1) and one C(11) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Eu(1) and one C(13) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Eu(1) and one C(13) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Eu(1), one C(14), and one H(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Eu(1) and one C(14) atom. In the thirteenth O site, O(13) is bonded in a distorted water-like geometry to one Eu(2), one H(1), and one H(2) atom. In the fourteenth O site, O(14) is bonded in a distorted water-like geometry to one Eu(2), one H(3), and one H(4) atom. Linkers: 8 Cc1nc(C([O])=O)c(C([O])=O)[nH]1 ,4 [O]C(=O)C([O])=O. Metal clusters: 8 [Eu]. The MOF has largest included sphere 4.24 A, density 2.06 g/cm3, surface area 2711.58 m2/g, accessible volume 0.17 cm3/g