AlSiO3OH crystallizes in the monoclinic P2_1/c space group. Al(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with four equivalent Si(1)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-54°. Si(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted SiO6 octahedra that share corners with two equivalent Si(1)O6 octahedra, corners with four equivalent Al(1)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-54°. H(1) is bonded in a distorted bent 150 degrees geometry to one O(3) and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Al(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(1) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded to two equivalent Al(1), one Si(1), and one H(1) atom to form edge-sharing OAl2SiH tetrahedra. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Al(1), one Si(1), and one H(1) atom.
AlSiO3OH crystallizes in the monoclinic P2_1/c space group. Al(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with four equivalent Si(1)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, and edges with two equivalent Si(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-54°. The Al(1)-O(1) bond length is 1.92 Å. The Al(1)-O(2) bond length is 1.89 Å. There is one shorter (1.92 Å) and one longer (1.94 Å) Al(1)-O(3) bond length. There is one shorter (1.90 Å) and one longer (1.97 Å) Al(1)-O(4) bond length. Si(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted SiO6 octahedra that share corners with two equivalent Si(1)O6 octahedra, corners with four equivalent Al(1)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-54°. The Si(1)-O(3) bond length is 1.75 Å. The Si(1)-O(4) bond length is 2.17 Å. There is one shorter (1.75 Å) and one longer (1.79 Å) Si(1)-O(1) bond length. There is one shorter (1.75 Å) and one longer (1.80 Å) Si(1)-O(2) bond length. H(1) is bonded in a distorted bent 150 degrees geometry to one O(3) and one O(4) atom. The H(1)-O(3) bond length is 1.60 Å. The H(1)-O(4) bond length is 1.02 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Al(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(1) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded to two equivalent Al(1), one Si(1), and one H(1) atom to form edge-sharing OAl2SiH tetrahedra. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Al(1), one Si(1), and one H(1) atom.