LiAlSiH2O5 crystallizes in the orthorhombic Pna2_1 space group. Li(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Al(1)O4 tetrahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Si(1)O4 tetrahedra. Al(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid,  an edgeedge with one Al(1)O4 tetrahedra, and  an edgeedge with one Li(1)O5 trigonal bipyramid. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to two equivalent Li(1), one H(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Al(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Al(1) and one Si(1) atom.
LiAlSiH2O5 crystallizes in the orthorhombic Pna2_1 space group. Li(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Al(1)O4 tetrahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Si(1)O4 tetrahedra. The Li(1)-O(1) bond length is 2.13 Å. The Li(1)-O(2) bond length is 2.06 Å. The Li(1)-O(4) bond length is 2.34 Å. There is one shorter (2.04 Å) and one longer (2.21 Å) Li(1)-O(3) bond length. Al(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Li(1)O5 trigonal bipyramids, and  an edgeedge with one Si(1)O4 tetrahedra. The Al(1)-O(1) bond length is 1.81 Å. The Al(1)-O(2) bond length is 1.84 Å. The Al(1)-O(4) bond length is 1.72 Å. The Al(1)-O(5) bond length is 1.74 Å. Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid,  an edgeedge with one Al(1)O4 tetrahedra, and  an edgeedge with one Li(1)O5 trigonal bipyramid. The Si(1)-O(1) bond length is 1.67 Å. The Si(1)-O(2) bond length is 1.70 Å. The Si(1)-O(4) bond length is 1.62 Å. The Si(1)-O(5) bond length is 1.61 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 0.97 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. The H(2)-O(3) bond length is 0.99 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to two equivalent Li(1), one H(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Al(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Al(1) and one Si(1) atom.