NaAlSi4 crystallizes in the tetragonal P4mm space group. Na(1) is bonded in a 1-coordinate geometry to one Si(3), four equivalent Si(1), and four equivalent Si(2) atoms. Al(1) is bonded in a 5-coordinate geometry to one Si(2) and four equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a body-centered cubic geometry to two equivalent Na(1), two equivalent Al(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Na(1), one Al(1), and four equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a distorted single-bond geometry to one Na(1) and four equivalent Si(1) atoms.
NaAlSi4 crystallizes in the tetragonal P4mm space group. Na(1) is bonded in a 1-coordinate geometry to one Si(3), four equivalent Si(1), and four equivalent Si(2) atoms. The Na(1)-Si(3) bond length is 2.73 Å. All Na(1)-Si(1) bond lengths are 3.01 Å. All Na(1)-Si(2) bond lengths are 3.15 Å. Al(1) is bonded in a 5-coordinate geometry to one Si(2) and four equivalent Si(1) atoms. The Al(1)-Si(2) bond length is 2.73 Å. All Al(1)-Si(1) bond lengths are 2.89 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a body-centered cubic geometry to two equivalent Na(1), two equivalent Al(1), two equivalent Si(2), and two equivalent Si(3) atoms. Both Si(1)-Si(2) bond lengths are 2.55 Å. Both Si(1)-Si(3) bond lengths are 2.47 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Na(1), one Al(1), and four equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a distorted single-bond geometry to one Na(1) and four equivalent Si(1) atoms.