Sr14Al8Ge3 crystallizes in the trigonal R-3 space group. There are seven inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), and three equivalent Ge(1) atoms. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), one Al(4), and two equivalent Ge(1) atoms. In the third Sr site, Sr(3) is bonded to one Al(1), two equivalent Al(2), and one Ge(1) atom to form distorted SrAl3Ge tetrahedra that share  a cornercorner with one Sr(7)Ge6 octahedra and corners with two equivalent Sr(3)Al3Ge tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one Al(1), one Al(4), three equivalent Al(2), and one Ge(1) atom. In the fifth Sr site, Sr(5) is bonded in a 6-coordinate geometry to three equivalent Al(2) and three equivalent Ge(1) atoms. In the sixth Sr site, Sr(6) is bonded in a 6-coordinate geometry to six equivalent Al(1) atoms. In the seventh Sr site, Sr(7) is bonded to six equivalent Ge(1) atoms to form corner-sharing SrGe6 octahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 8-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Sr(6), one Al(3), and two equivalent Al(1) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Sr(5), two equivalent Sr(3), three equivalent Sr(4), one Al(4), and two equivalent Al(2) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to three equivalent Sr(1), three equivalent Sr(2), and three equivalent Al(1) atoms. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to three equivalent Sr(2), three equivalent Sr(4), and three equivalent Al(2) atoms. Ge(1) is bonded in a 9-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(7), two equivalent Sr(2), and three equivalent Sr(1) atoms.
Sr14Al8Ge3 crystallizes in the trigonal R-3 space group. There are seven inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), and three equivalent Ge(1) atoms. The Sr(1)-Al(1) bond length is 3.43 Å. The Sr(1)-Al(3) bond length is 3.43 Å. There are a spread of Sr(1)-Ge(1) bond distances ranging from 3.29-3.36 Å. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), one Al(4), and two equivalent Ge(1) atoms. The Sr(2)-Al(1) bond length is 3.52 Å. The Sr(2)-Al(3) bond length is 3.59 Å. The Sr(2)-Al(4) bond length is 3.49 Å. There is one shorter (3.28 Å) and one longer (3.73 Å) Sr(2)-Ge(1) bond length. In the third Sr site, Sr(3) is bonded to one Al(1), two equivalent Al(2), and one Ge(1) atom to form distorted SrAl3Ge tetrahedra that share  a cornercorner with one Sr(7)Ge6 octahedra and corners with two equivalent Sr(3)Al3Ge tetrahedra. The corner-sharing octahedral tilt angles are 59°. The Sr(3)-Al(1) bond length is 3.32 Å. There is one shorter (3.40 Å) and one longer (3.58 Å) Sr(3)-Al(2) bond length. The Sr(3)-Ge(1) bond length is 3.42 Å. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one Al(1), one Al(4), three equivalent Al(2), and one Ge(1) atom. The Sr(4)-Al(1) bond length is 3.39 Å. The Sr(4)-Al(4) bond length is 3.39 Å. There are a spread of Sr(4)-Al(2) bond distances ranging from 3.36-3.53 Å. The Sr(4)-Ge(1) bond length is 3.28 Å. In the fifth Sr site, Sr(5) is bonded in a 6-coordinate geometry to three equivalent Al(2) and three equivalent Ge(1) atoms. All Sr(5)-Al(2) bond lengths are 3.46 Å. All Sr(5)-Ge(1) bond lengths are 3.32 Å. In the sixth Sr site, Sr(6) is bonded in a 6-coordinate geometry to six equivalent Al(1) atoms. All Sr(6)-Al(1) bond lengths are 3.73 Å. In the seventh Sr site, Sr(7) is bonded to six equivalent Ge(1) atoms to form corner-sharing SrGe6 octahedra. All Sr(7)-Ge(1) bond lengths are 3.54 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 8-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Sr(6), one Al(3), and two equivalent Al(1) atoms. The Al(1)-Al(3) bond length is 2.74 Å. Both Al(1)-Al(1) bond lengths are 2.70 Å. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Sr(5), two equivalent Sr(3), three equivalent Sr(4), one Al(4), and two equivalent Al(2) atoms. The Al(2)-Al(4) bond length is 2.73 Å. Both Al(2)-Al(2) bond lengths are 2.70 Å. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to three equivalent Sr(1), three equivalent Sr(2), and three equivalent Al(1) atoms. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to three equivalent Sr(2), three equivalent Sr(4), and three equivalent Al(2) atoms. Ge(1) is bonded in a 9-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(7), two equivalent Sr(2), and three equivalent Sr(1) atoms.