Na4Ga8Ge15 crystallizes in the cubic Pm-3n space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted body-centered cubic geometry to eight equivalent Ga(1) atoms. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to eight equivalent Ge(2) atoms. Ga(1) is bonded in a 5-coordinate geometry to one Na(1), one Ga(1), and three equivalent Ge(2) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to four equivalent Ge(2) atoms. In the second Ge site, Ge(2) is bonded in a 4-coordinate geometry to two equivalent Na(2), two equivalent Ga(1), one Ge(1), and one Ge(2) atom.
Na4Ga8Ge15 crystallizes in the cubic Pm-3n space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted body-centered cubic geometry to eight equivalent Ga(1) atoms. All Na(1)-Ga(1) bond lengths are 3.43 Å. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to eight equivalent Ge(2) atoms. All Na(2)-Ge(2) bond lengths are 3.62 Å. Ga(1) is bonded in a 5-coordinate geometry to one Na(1), one Ga(1), and three equivalent Ge(2) atoms. The Ga(1)-Ga(1) bond length is 2.55 Å. All Ga(1)-Ge(2) bond lengths are 2.53 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to four equivalent Ge(2) atoms. All Ge(1)-Ge(2) bond lengths are 2.52 Å. In the second Ge site, Ge(2) is bonded in a 4-coordinate geometry to two equivalent Na(2), two equivalent Ga(1), one Ge(1), and one Ge(2) atom. The Ge(2)-Ge(2) bond length is 2.50 Å.