Materials Data on ScAl3 by Materials Project

Abstract

Al3Sc is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sc is bonded to twelve Al atoms to form ScAl12 cuboctahedra that share corners with four equivalent ScAl12 cuboctahedra, edges with eight equivalent ScAl12 cuboctahedra, edges with sixteen equivalent AlSc4Al8 cuboctahedra, faces with four equivalent ScAl12 cuboctahedra, and faces with eight equivalent AlSc4Al8 cuboctahedra. There are four shorter (2.85 Å) and eight longer (2.99 Å) Sc–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Sc and eight Al atoms to form AlSc4Al8 cuboctahedra that share corners with twelve equivalent AlSc4Al8 cuboctahedra, edges with eight equivalent ScAl12 cuboctahedra, edges with eight equivalent AlSc4Al8 cuboctahedra, faces with four equivalent ScAl12 cuboctahedra, and faces with ten equivalent AlSc4Al8 cuboctahedra. There are four shorter (2.85 Å) and four longer (2.99 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a distorted square co-planar geometry to four equivalent Sc and eight equivalent Al atoms.