Materials Data on NaAlSi4 by Materials Project
NaAlSi4 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. Na is bonded in a 1-coordinate geometry to nine Si atoms. There are a spread of Na–Si bond distances ranging from 2.70–3.09 Å. Al is bonded in a distorted single-bond geometry to five Si atoms. There are one shorter (2.66 Å) and four longer (3.02 Å) Al–Si bond lengths. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to two equivalent Na, two equivalent Al, and four Si atoms. There are two shorter (2.48 Å) and two longer (2.52 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a distorted single-bond geometry to one Na and four equivalent Si atoms. In the third Si site, Si is bonded in a 9-coordinate geometry to four equivalent Na, one Al, and four equivalent Si atoms.