AlSi3O8 is quartz (alpha)-derived structured and crystallizes in the triclinic P-1 space group. Al(1) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. There are eight 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(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Al(1) and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom.
AlSi3O8 is quartz (alpha)-derived structured and crystallizes in the triclinic P-1 space group. Al(1) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Al(1)-O(1) bond length is 1.77 Å. The Al(1)-O(4) bond length is 1.76 Å. The Al(1)-O(6) bond length is 1.74 Å. The Al(1)-O(7) bond length is 1.75 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.65 Å. The Si(1)-O(5) bond length is 1.63 Å. The Si(1)-O(7) bond length is 1.60 Å. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. The Si(2)-O(1) bond length is 1.62 Å. The Si(2)-O(4) bond length is 1.63 Å. The Si(2)-O(5) bond length is 1.63 Å. The Si(2)-O(8) bond length is 1.63 Å. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The Si(3)-O(2) bond length is 1.64 Å. The Si(3)-O(3) bond length is 1.64 Å. The Si(3)-O(6) bond length is 1.61 Å. The Si(3)-O(8) bond length is 1.64 Å. There are eight 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(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Al(1) and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom.