Materials Data on SrAl9Co2 by Materials Project

Abstract

SrCo2Al9 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Sr is bonded to twelve equivalent Al atoms to form face-sharing SrAl12 cuboctahedra. All Sr–Al bond lengths are 3.53 Å. Co is bonded in a 9-coordinate geometry to nine Al atoms. There are three shorter (2.28 Å) and six longer (2.55 Å) Co–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a linear geometry to two equivalent Co and eight equivalent Al atoms. All Al–Al bond lengths are 2.82 Å. In the second Al site, Al is bonded in a 2-coordinate geometry to two equivalent Sr, two equivalent Co, and eight Al atoms. There are two shorter (2.83 Å) and two longer (2.93 Å) Al–Al bond lengths.