Al4Si2H(O3F)3 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(5), one O(7), one O(8), one O(9), and two equivalent F(2) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(2)O4F2 octahedra, and  an edgeedge with one Al(4)O4F2 octahedra. The corner-sharing octahedral tilt angles are 35°. In the second Al site, Al(2) is bonded to one O(4), one O(6), one O(8), one O(9), and two equivalent F(3) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(2)O4F2 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(1)O4F2 octahedra, and  an edgeedge with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles are 35°. In the third Al site, Al(3) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(2) atoms to form AlO6 octahedra that share corners with two equivalent Al(3)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(2)O4F2 octahedra, and  an edgeedge with one Al(4)O4F2 octahedra. The corner-sharing octahedral tilt angles are 41°. In the fourth Al site, Al(4) is bonded to one O(1), one O(3), one O(5), one O(7), and two equivalent F(1) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(4)O4F2 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(1)O4F2 octahedra, and  an edgeedge with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with two equivalent Al(2)O4F2 octahedra, corners with two equivalent Al(4)O4F2 octahedra, and corners with two equivalent Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with two equivalent Al(2)O4F2 octahedra, corners with two equivalent Al(4)O4F2 octahedra, and corners with two equivalent Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. H(1) is bonded in a single-bond geometry to one O(2) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Al(3), one Al(4), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Al(3) and one H(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Al(3), one Al(4), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(4), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(4), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(2) atom. There are three inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Al(4) atoms. In the second F site, F(2) is bonded in a bent 150 degrees geometry to two equivalent Al(1) atoms. In the third F site, F(3) is bonded in a bent 150 degrees geometry to two equivalent Al(2) atoms.
Al4Si2H(O3F)3 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(5), one O(7), one O(8), one O(9), and two equivalent F(2) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(2)O4F2 octahedra, and  an edgeedge with one Al(4)O4F2 octahedra. The corner-sharing octahedral tilt angles are 35°. The Al(1)-O(5) bond length is 1.90 Å. The Al(1)-O(7) bond length is 1.92 Å. The Al(1)-O(8) bond length is 1.91 Å. The Al(1)-O(9) bond length is 1.91 Å. Both Al(1)-F(2) bond lengths are 1.82 Å. In the second Al site, Al(2) is bonded to one O(4), one O(6), one O(8), one O(9), and two equivalent F(3) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(2)O4F2 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(1)O4F2 octahedra, and  an edgeedge with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles are 35°. The Al(2)-O(4) bond length is 1.91 Å. The Al(2)-O(6) bond length is 1.91 Å. The Al(2)-O(8) bond length is 1.92 Å. The Al(2)-O(9) bond length is 1.92 Å. There is one shorter (1.81 Å) and one longer (1.82 Å) Al(2)-F(3) bond length. In the third Al site, Al(3) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(2) atoms to form AlO6 octahedra that share corners with two equivalent Al(3)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(2)O4F2 octahedra, and  an edgeedge with one Al(4)O4F2 octahedra. The corner-sharing octahedral tilt angles are 41°. The Al(3)-O(1) bond length is 1.97 Å. The Al(3)-O(3) bond length is 1.96 Å. The Al(3)-O(4) bond length is 1.94 Å. The Al(3)-O(6) bond length is 1.94 Å. Both Al(3)-O(2) bond lengths are 1.83 Å. In the fourth Al site, Al(4) is bonded to one O(1), one O(3), one O(5), one O(7), and two equivalent F(1) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(4)O4F2 octahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Al(1)O4F2 octahedra, and  an edgeedge with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. The Al(4)-O(1) bond length is 1.94 Å. The Al(4)-O(3) bond length is 1.90 Å. The Al(4)-O(5) bond length is 1.91 Å. The Al(4)-O(7) bond length is 1.90 Å. There is one shorter (1.83 Å) and one longer (1.84 Å) Al(4)-F(1) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with two equivalent Al(2)O4F2 octahedra, corners with two equivalent Al(4)O4F2 octahedra, and corners with two equivalent Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. The Si(1)-O(1) bond length is 1.67 Å. The Si(1)-O(6) bond length is 1.66 Å. The Si(1)-O(7) bond length is 1.66 Å. The Si(1)-O(8) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with two equivalent Al(2)O4F2 octahedra, corners with two equivalent Al(4)O4F2 octahedra, and corners with two equivalent Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The Si(2)-O(3) bond length is 1.66 Å. The Si(2)-O(4) bond length is 1.66 Å. The Si(2)-O(5) bond length is 1.66 Å. The Si(2)-O(9) bond length is 1.66 Å. H(1) is bonded in a single-bond geometry to one O(2) atom. The H(1)-O(2) bond length is 0.97 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Al(3), one Al(4), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Al(3) and one H(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Al(3), one Al(4), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(4), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(4), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(2) atom. There are three inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Al(4) atoms. In the second F site, F(2) is bonded in a bent 150 degrees geometry to two equivalent Al(1) atoms. In the third F site, F(3) is bonded in a bent 150 degrees geometry to two equivalent Al(2) atoms.