BaAl3P2(HO7)2 crystallizes in the monoclinic C2/m space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2), four equivalent O(3), and four equivalent O(5) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2) and four equivalent O(5) atoms to form distorted AlO6 octahedra that share corners with four equivalent Al(2)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. In the second Al site, Al(2) 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 Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-60°. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra and corners with two equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. H(1) is bonded in a single-bond geometry to one O(4) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(1), one Al(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Al(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Al(2) and one H(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ba(1), one Al(1), one Al(2), and one O(5) atom.
BaAl3P2(HO7)2 crystallizes in the monoclinic C2/m space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2), four equivalent O(3), and four equivalent O(5) atoms. Both Ba(1)-O(2) bond lengths are 2.99 Å. All Ba(1)-O(3) bond lengths are 2.87 Å. All Ba(1)-O(5) bond lengths are 2.73 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2) and four equivalent O(5) atoms to form distorted AlO6 octahedra that share corners with four equivalent Al(2)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. Both Al(1)-O(2) bond lengths are 1.89 Å. All Al(1)-O(5) bond lengths are 1.86 Å. In the second Al site, Al(2) 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 Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-60°. Both Al(2)-O(3) bond lengths are 1.92 Å. Both Al(2)-O(4) bond lengths are 1.89 Å. Both Al(2)-O(5) bond lengths are 1.93 Å. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra and corners with two equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.57 Å. Both P(1)-O(3) bond lengths are 1.57 Å. H(1) is bonded in a single-bond geometry to one O(4) atom. The H(1)-O(4) bond length is 0.99 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(1), one Al(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Al(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Al(2) and one H(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ba(1), one Al(1), one Al(2), and one O(5) atom. The O(5)-O(5) bond length is 1.54 Å.