Materials Data on NaAl3 by Materials Project
NaAl3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Na is bonded to twelve Al atoms to form NaAl12 cuboctahedra that share corners with four equivalent NaAl12 cuboctahedra, corners with eight equivalent AlNa4Al8 cuboctahedra, edges with eight equivalent NaAl12 cuboctahedra, faces with four equivalent NaAl12 cuboctahedra, and faces with six equivalent AlNa4Al8 cuboctahedra. There are eight shorter (2.96 Å) and four longer (3.09 Å) Na–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 4-coordinate geometry to four equivalent Na and four equivalent Al atoms. All Al–Al bond lengths are 2.96 Å. In the second Al site, Al is bonded to four equivalent Na and eight equivalent Al atoms to form AlNa4Al8 cuboctahedra that share corners with four equivalent AlNa4Al8 cuboctahedra, corners with eight equivalent NaAl12 cuboctahedra, edges with eight equivalent AlNa4Al8 cuboctahedra, faces with four equivalent AlNa4Al8 cuboctahedra, and faces with six equivalent NaAl12 cuboctahedra.