GdC5AsNH6O8CH crystallizes in the monoclinic P2_1/c space group. The structure consists of four 02329_fluka molecules inside a GdC5AsNH6O8 framework. In the GdC5AsNH6O8 framework, Gd(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), one O(7), one O(8), two equivalent O(1), and two equivalent O(2) atoms. The Gd(1)-O(4) bond length is 2.31 Å. The Gd(1)-O(5) bond length is 2.55 Å. The Gd(1)-O(7) bond length is 2.37 Å. The Gd(1)-O(8) bond length is 2.48 Å. There is one shorter (2.25 Å) and one longer (2.49 Å) Gd(1)-O(1) bond length. There is one shorter (2.29 Å) and one longer (2.45 Å) Gd(1)-O(2) bond length. There are five inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one As(1) atom. The C(1)-C(2) bond length is 1.42 Å. The C(1)-C(6) bond length is 1.38 Å. The C(1)-As(1) bond length is 1.91 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1) and one H(1) atom. The C(2)-H(1) bond length is 1.09 Å. In the third C site, C(4) is bonded in a distorted single-bond geometry to one C(5) and one O(4) atom. The C(4)-C(5) bond length is 1.45 Å. The C(4)-O(4) bond length is 1.28 Å. In the fourth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one C(6), and one N(1) atom. The C(5)-C(6) bond length is 1.41 Å. The C(5)-N(1) bond length is 1.42 Å. In the fifth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(3) atom. The C(6)-H(3) bond length is 1.09 Å. As(1) is bonded in a tetrahedral geometry to one C(1), one O(1), one O(2), and one O(3) atom. The As(1)-O(1) bond length is 1.73 Å. The As(1)-O(2) bond length is 1.74 Å. The As(1)-O(3) bond length is 1.69 Å. N(1) is bonded in a trigonal planar geometry to one C(5), one O(5), and one O(6) atom. The N(1)-O(5) bond length is 1.26 Å. The N(1)-O(6) bond length is 1.26 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(3) is bonded in a single-bond geometry to one C(6) atom. In the third H site, H(4) is bonded in a single-bond geometry to one O(7) atom. The H(4)-O(7) bond length is 0.98 Å. In the fourth H site, H(5) is bonded in a distorted single-bond geometry to one O(3) and one O(7) atom. The H(5)-O(3) bond length is 1.63 Å. The H(5)-O(7) bond length is 1.01 Å. In the fifth H site, H(6) is bonded in a single-bond geometry to one O(8) atom. The H(6)-O(8) bond length is 0.98 Å. In the sixth H site, H(7) is bonded in a distorted single-bond geometry to one O(3) and one O(8) atom. The H(7)-O(3) bond length is 1.63 Å. The H(7)-O(8) bond length is 1.01 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one As(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one As(1), one H(5), and one H(7) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Gd(1) and one C(4) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Gd(1) and one N(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one N(1) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Gd(1), one H(4), and one H(5) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Gd(1), one H(6), and one H(7) atom. Linkers: 4 [O][As]([O])[O].[O]c1cc[c]cc1[N+](=O)[O-]. Metal clusters: 4 [Gd]. RCSR code: fes. The MOF has largest included sphere 1.71 A, density 2.99 g/cm3, surface area 2233.05 m2/g, accessible volume 0.03 cm3/g