NaNa2Si17 crystallizes in the cubic Fd-3m space group. The structure consists of eight 7440-23-5 atoms inside a Na2Si17 framework. In the Na2Si17 framework, Na(2) is bonded in a 20-coordinate geometry to two equivalent Si(1), six equivalent Si(2), and twelve equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a body-centered cubic geometry to four equivalent Na(2) and four equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to three equivalent Na(2), one Si(1), and three equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 6-coordinate geometry to two equivalent Na(2), one Si(2), and three equivalent Si(3) atoms.
NaNa2Si17 crystallizes in the cubic Fd-3m space group. The structure consists of eight 7440-23-5 atoms inside a Na2Si17 framework. In the Na2Si17 framework, Na(2) is bonded in a 20-coordinate geometry to two equivalent Si(1), six equivalent Si(2), and twelve equivalent Si(3) atoms. Both Na(2)-Si(1) bond lengths are 3.18 Å. All Na(2)-Si(2) bond lengths are 3.27 Å. All Na(2)-Si(3) bond lengths are 3.37 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a body-centered cubic geometry to four equivalent Na(2) and four equivalent Si(2) atoms. All Si(1)-Si(2) bond lengths are 2.37 Å. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to three equivalent Na(2), one Si(1), and three equivalent Si(3) atoms. All Si(2)-Si(3) bond lengths are 2.37 Å. In the third Si site, Si(3) is bonded in a 6-coordinate geometry to two equivalent Na(2), one Si(2), and three equivalent Si(3) atoms. There are two shorter (2.36 Å) and one longer (2.39 Å) Si(3)-Si(3) bond length.