Ga2CP2O10 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(9) atom to form GaO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. The Ga(1)-O(1) bond length is 1.91 Å. The Ga(1)-O(2) bond length is 2.12 Å. The Ga(1)-O(3) bond length is 2.04 Å. The Ga(1)-O(4) bond length is 1.89 Å. The Ga(1)-O(5) bond length is 1.94 Å. The Ga(1)-O(9) bond length is 1.93 Å. In the second Ga site, Ga(2) is bonded to one O(10), one O(6), one O(7), and one O(8) atom to form GaO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. The Ga(2)-O(10) bond length is 1.84 Å. The Ga(2)-O(6) bond length is 1.82 Å. The Ga(2)-O(7) bond length is 1.82 Å. The Ga(2)-O(8) bond length is 1.83 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to two equivalent O(2) atoms. Both C(1)-O(2) bond lengths are 1.25 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to two equivalent O(3) atoms. Both C(2)-O(3) bond lengths are 1.25 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Ga(1)O6 octahedra and corners with two equivalent Ga(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-49°. The P(1)-O(4) bond length is 1.51 Å. The P(1)-O(5) bond length is 1.52 Å. The P(1)-O(6) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(1), one O(10), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Ga(1)O6 octahedra and corners with two equivalent Ga(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-45°. The P(2)-O(1) bond length is 1.49 Å. The P(2)-O(10) bond length is 1.56 Å. The P(2)-O(8) bond length is 1.56 Å. The P(2)-O(9) bond length is 1.52 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ga(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ga(1) and one C(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ga(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ga(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ga(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ga(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ga(2) and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Ga(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Ga(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Ga(2) and one P(2) atom. Linkers: 4 [O]C(=O)C([O])=O. Metal clusters: 16 [Ga]. The MOF has largest included sphere 4.46 A, density 2.51 g/cm3, surface area 2107.03 m2/g, accessible volume 0.14 cm3/g