Materials Data on Sr3(AlGe2)2 by Materials Project

Abstract

Sr3(AlGe2)2 is Magnesium tetraboride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 9-coordinate geometry to two equivalent Al and seven Ge atoms. Both Sr–Al bond lengths are 3.30 Å. There are a spread of Sr–Ge bond distances ranging from 3.11–3.39 Å. In the second Sr site, Sr is bonded to six Ge atoms to form distorted edge-sharing SrGe6 octahedra. There are two shorter (3.29 Å) and four longer (3.32 Å) Sr–Ge bond lengths. Al is bonded in a 4-coordinate geometry to two equivalent Sr and four Ge atoms. There are a spread of Al–Ge bond distances ranging from 2.55–2.70 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 8-coordinate geometry to five Sr, one Al, and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.66 Å. In the second Ge site, Ge is bonded in a 8-coordinate geometry to five Sr and three equivalent Al atoms.