LiAlSiH2O5 crystallizes in the orthorhombic Pna2_1 space group. Li(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), and two equivalent O(2) atoms. Al(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and  an edgeedge with one Al(1)O4 tetrahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one O(2) and one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one H(1), and one H(2) atom to form distorted OLi2H2 tetrahedra that share corners with two equivalent O(2)Li2H2 tetrahedra and corners with three equivalent O(3)LiAlSiH trigonal pyramids. In the third O site, O(3) is bonded to one Li(1), one Al(1), one Si(1), and one H(1) atom to form distorted corner-sharing OLiAlSiH trigonal pyramids. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Li(1), one Al(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted L-shaped geometry to one Li(1), one Al(1), and one Si(1) atom.
LiAlSiH2O5 crystallizes in the orthorhombic Pna2_1 space group. Li(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), and two equivalent O(2) atoms. The Li(1)-O(3) bond length is 2.14 Å. The Li(1)-O(4) bond length is 2.20 Å. The Li(1)-O(5) bond length is 2.58 Å. There is one shorter (2.07 Å) and one longer (2.08 Å) Li(1)-O(2) bond length. Al(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and  an edgeedge with one Si(1)O4 tetrahedra. The Al(1)-O(1) bond length is 1.74 Å. The Al(1)-O(3) bond length is 1.83 Å. The Al(1)-O(4) bond length is 1.72 Å. The Al(1)-O(5) bond length is 1.82 Å. Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and  an edgeedge with one Al(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.71 Å. The Si(1)-O(4) bond length is 1.61 Å. The Si(1)-O(5) bond length is 1.65 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one O(2) and one O(3) atom. The H(1)-O(2) bond length is 1.02 Å. The H(1)-O(3) bond length is 1.62 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. The H(2)-O(2) bond length is 0.98 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one H(1), and one H(2) atom to form distorted OLi2H2 tetrahedra that share corners with two equivalent O(2)Li2H2 tetrahedra and corners with three equivalent O(3)LiAlSiH trigonal pyramids. In the third O site, O(3) is bonded to one Li(1), one Al(1), one Si(1), and one H(1) atom to form distorted corner-sharing OLiAlSiH trigonal pyramids. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Li(1), one Al(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted L-shaped geometry to one Li(1), one Al(1), and one Si(1) atom.