Al2PH3O7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra,  an edgeedge with one Al(1)O6 octahedra, and edges with two equivalent Al(2)O5 trigonal bipyramids. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(4), and two equivalent O(5) atoms to form distorted AlO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra and edges with two equivalent Al(1)O6 octahedra. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent Al(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 32°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Al(2), two equivalent Al(1), and one H(1) atom. In the second O site, O(5) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one H(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Al(2) and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Al(2) and one P(1) atom. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom.
Al2PH3O7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra,  an edgeedge with one Al(1)O6 octahedra, and edges with two equivalent Al(2)O5 trigonal bipyramids. Both Al(1)-O(3) bond lengths are 1.85 Å. Both Al(1)-O(4) bond lengths are 2.01 Å. Both Al(1)-O(5) bond lengths are 1.88 Å. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(4), and two equivalent O(5) atoms to form distorted AlO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra and edges with two equivalent Al(1)O6 octahedra. The Al(2)-O(1) bond length is 1.83 Å. The Al(2)-O(2) bond length is 1.78 Å. The Al(2)-O(4) bond length is 2.08 Å. Both Al(2)-O(5) bond lengths are 1.79 Å. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent Al(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 32°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.55 Å. Both P(1)-O(3) bond lengths are 1.54 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. The H(1)-O(4) bond length is 0.98 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.98 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Al(2), two equivalent Al(1), and one H(1) atom. In the second O site, O(5) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one H(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Al(2) and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Al(2) and one P(1) atom. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom.