Materials Data on Sr2Al3Ge by Materials Project
Sr2Al3Ge is hexagonal omega structure-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Sr is bonded to nine Al and three equivalent Ge atoms to form a mixture of edge and face-sharing SrAl9Ge3 cuboctahedra. There are six shorter (3.50 Å) and three longer (3.52 Å) Sr–Al bond lengths. All Sr–Ge bond lengths are 3.52 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 9-coordinate geometry to six equivalent Sr and three equivalent Al atoms. All Al–Al bond lengths are 2.55 Å. In the second Al site, Al is bonded in a distorted trigonal planar geometry to six equivalent Sr and three equivalent Ge atoms. All Al–Ge bond lengths are 2.55 Å. In the third Al site, Al is bonded in a 9-coordinate geometry to six equivalent Sr and three equivalent Al atoms. Ge is bonded in a distorted trigonal planar geometry to six equivalent Sr and three equivalent Al atoms.