GaC5AsNH4O4 crystallizes in the triclinic P-1 space group. Ga(1) is bonded to one N(1), one O(1), one O(2), one O(3), and one O(4) atom to form distorted GaNO4 trigonal bipyramids that share corners with four equivalent As(1)O4 tetrahedra. The Ga(1)-N(1) bond length is 2.20 Å. The Ga(1)-O(1) bond length is 1.96 Å. The Ga(1)-O(2) bond length is 1.88 Å. The Ga(1)-O(3) bond length is 1.89 Å. The Ga(1)-O(4) bond length is 1.90 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one N(1), and one H(1) atom. The C(1)-C(2) bond length is 1.39 Å. The C(1)-N(1) bond length is 1.34 Å. The C(1)-H(1) bond length is 1.09 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one H(3) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(3) bond length is 1.09 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(4) atom. The C(3)-C(3) bond length is 1.48 Å. The C(3)-C(4) bond length is 1.40 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(2) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-H(2) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one H(4) atom. The C(5)-N(1) bond length is 1.34 Å. The C(5)-H(4) bond length is 1.09 Å. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with four equivalent Ga(1)NO4 trigonal bipyramids. The As(1)-O(1) bond length is 1.71 Å. The As(1)-O(2) bond length is 1.70 Å. The As(1)-O(3) bond length is 1.73 Å. The As(1)-O(4) bond length is 1.73 Å. N(1) is bonded in a trigonal planar geometry to one Ga(1), one C(1), and one C(5) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(5) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ga(1) and one As(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ga(1) and one As(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ga(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Ga(1) and one As(1) atom. Linkers: 2 [O].[O][As]([O])[O]. Metal clusters: 2 [Ga]. The MOF has largest included sphere 1.62 A, density 2.72 g/cm3, surface area 2575.77 m2/g, accessible volume 0.07 cm3/g