Materials Data on Sr4Mg3Al5 by Materials Project

Sr4Mg3Al5 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 12-coordinate geometry to four Sr, three equivalent Mg, and nine Al atoms. There are one shorter (3.55 Å) and three longer (3.68 Å) Sr–Sr bond lengths. All Sr–Mg bond lengths are 3.66 Å. There are six shorter (3.51 Å) and three longer (3.52 Å) Sr–Al bond lengths. In the second Sr site, Sr is bonded in a 12-coordinate geometry to three equivalent Sr, six equivalent Mg, and six Al atoms. All Sr–Mg bond lengths are 3.65 Å. There are three shorter (3.41 Å) and three longer (3.57 Å) Sr–Al bond lengths. Mg is bonded to six Sr, four equivalent Mg, and two equivalent Al atoms to form MgSr6Mg4Al2 cuboctahedra that share corners with four equivalent MgSr6Mg4Al2 cuboctahedra, corners with fourteen AlSr6Al6 cuboctahedra, edges with two equivalent MgSr6Mg4Al2 cuboctahedra, edges with four equivalent AlSr6Al6 cuboctahedra, faces with eight equivalent MgSr6Mg4Al2 cuboctahedra, and faces with ten AlSr6Mg3Al3 cuboctahedra. All Mg–Mg bond lengths are 3.02 Å. Both Mg–Al bond lengths are 3.29 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to six Sr, three equivalent Mg, and three equivalent Al atoms to form AlSr6Mg3Al3 cuboctahedra that share corners with six equivalent MgSr6Mg4Al2 cuboctahedra, corners with nine AlSr6Mg3Al3 cuboctahedra, edges with six equivalent AlSr6Mg3Al3 cuboctahedra, faces with nine equivalent MgSr6Mg4Al2 cuboctahedra, and faces with ten AlSr6Mg3Al3 cuboctahedra. All Al–Al bond lengths are 2.82 Å. In the second Al site, Al is bonded to six Sr and six Al atoms to form distorted AlSr6Al6 cuboctahedra that share corners with eight AlSr6Al6 cuboctahedra, corners with ten equivalent MgSr6Mg4Al2 cuboctahedra, edges with two equivalent AlSr6Al6 cuboctahedra, edges with four equivalent MgSr6Mg4Al2 cuboctahedra, faces with four equivalent MgSr6Mg4Al2 cuboctahedra, and faces with fourteen AlSr6Mg3Al3 cuboctahedra. There are two shorter (3.00 Å) and two longer (3.05 Å) Al–Al bond lengths.