Na4Al3Si3O12I crystallizes in the cubic P-43n space group. Na(1) is bonded in a 4-coordinate geometry to three equivalent O(1) and one I(1) atom. Al(1) is bonded to four equivalent O(1) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to four equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra. O(1) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one Si(1) atom. I(1) is bonded in a tetrahedral geometry to four equivalent Na(1) atoms.
Na4Al3Si3O12I crystallizes in the cubic P-43n space group. Na(1) is bonded in a 4-coordinate geometry to three equivalent O(1) and one I(1) atom. All Na(1)-O(1) bond lengths are 2.38 Å. The Na(1)-I(1) bond length is 3.15 Å. Al(1) is bonded to four equivalent O(1) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. All Al(1)-O(1) bond lengths are 1.76 Å. Si(1) is bonded to four equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra. All Si(1)-O(1) bond lengths are 1.64 Å. O(1) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one Si(1) atom. I(1) is bonded in a tetrahedral geometry to four equivalent Na(1) atoms.