Na3Al3Si3O16 crystallizes in the trigonal R3c space group. Na(1) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted hexagonal planar geometry to three equivalent Na(1) and three equivalent O(6) atoms. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one O(5) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Na(1), one Al(1), and one Si(1) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Al(1), and one Si(1) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Al(1), and one Si(1) atom.
Na3Al3Si3O16 crystallizes in the trigonal R3c space group. Na(1) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms. The Na(1)-O(2) bond length is 2.37 Å. The Na(1)-O(3) bond length is 2.35 Å. The Na(1)-O(4) bond length is 2.37 Å. The Na(1)-O(5) bond length is 2.67 Å. There is one shorter (2.62 Å) and one longer (2.63 Å) Na(1)-O(6) bond length. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. The Al(1)-O(1) bond length is 1.74 Å. The Al(1)-O(2) bond length is 1.76 Å. The Al(1)-O(3) bond length is 1.76 Å. The Al(1)-O(4) bond length is 1.77 Å. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.62 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.63 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted hexagonal planar geometry to three equivalent Na(1) and three equivalent O(6) atoms. All O(5)-O(6) bond lengths are 1.75 Å. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one O(5) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Na(1), one Al(1), and one Si(1) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Al(1), and one Si(1) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Al(1), and one Si(1) atom.