Materials Data on Na4Si23 by Materials Project
Na4Si23 crystallizes in the cubic Pm-3n space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight equivalent Si+0.17- atoms. All Na–Si bond lengths are 3.45 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to twenty Si+0.17- atoms. There are eight shorter (3.27 Å) and twelve longer (3.37 Å) Na–Si bond lengths. There are three inequivalent Si+0.17- sites. In the first Si+0.17- site, Si+0.17- is bonded in a distorted pentagonal planar geometry to one Na1+ and four Si+0.17- atoms. There are one shorter (2.34 Å) and three longer (2.37 Å) Si–Si bond lengths. In the second Si+0.17- site, Si+0.17- is bonded in a tetrahedral geometry to four equivalent Si+0.17- atoms. All Si–Si bond lengths are 2.39 Å. In the third Si+0.17- site, Si+0.17- is bonded in a 4-coordinate geometry to three Na1+ and four Si+0.17- atoms. The Si–Si bond length is 2.40 Å.