AlGe3 crystallizes in the tetragonal I4/mmm space group. Al(1) is bonded to four equivalent Ge(2) and eight equivalent Ge(1) atoms to form AlGe12 cuboctahedra that share corners with four equivalent Al(1)Ge12 cuboctahedra, edges with eight equivalent Al(1)Ge12 cuboctahedra, edges with sixteen equivalent Ge(1)Al4Ge8 cuboctahedra, faces with four equivalent Al(1)Ge12 cuboctahedra, and faces with eight equivalent Ge(1)Al4Ge8 cuboctahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to four equivalent Al(1), four equivalent Ge(1), and four equivalent Ge(2) atoms to form distorted GeAl4Ge8 cuboctahedra that share corners with twelve equivalent Ge(1)Al4Ge8 cuboctahedra, edges with eight equivalent Al(1)Ge12 cuboctahedra, edges with eight equivalent Ge(1)Al4Ge8 cuboctahedra, faces with four equivalent Al(1)Ge12 cuboctahedra, and faces with ten equivalent Ge(1)Al4Ge8 cuboctahedra. In the second Ge site, Ge(2) is bonded in a square co-planar geometry to four equivalent Al(1) and eight equivalent Ge(1) atoms.
AlGe3 crystallizes in the tetragonal I4/mmm space group. Al(1) is bonded to four equivalent Ge(2) and eight equivalent Ge(1) atoms to form AlGe12 cuboctahedra that share corners with four equivalent Al(1)Ge12 cuboctahedra, edges with eight equivalent Al(1)Ge12 cuboctahedra, edges with sixteen equivalent Ge(1)Al4Ge8 cuboctahedra, faces with four equivalent Al(1)Ge12 cuboctahedra, and faces with eight equivalent Ge(1)Al4Ge8 cuboctahedra. All Al(1)-Ge(2) bond lengths are 2.86 Å. All Al(1)-Ge(1) bond lengths are 3.05 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to four equivalent Al(1), four equivalent Ge(1), and four equivalent Ge(2) atoms to form distorted GeAl4Ge8 cuboctahedra that share corners with twelve equivalent Ge(1)Al4Ge8 cuboctahedra, edges with eight equivalent Al(1)Ge12 cuboctahedra, edges with eight equivalent Ge(1)Al4Ge8 cuboctahedra, faces with four equivalent Al(1)Ge12 cuboctahedra, and faces with ten equivalent Ge(1)Al4Ge8 cuboctahedra. All Ge(1)-Ge(1) bond lengths are 2.86 Å. All Ge(1)-Ge(2) bond lengths are 3.05 Å. In the second Ge site, Ge(2) is bonded in a square co-planar geometry to four equivalent Al(1) and eight equivalent Ge(1) atoms.