  Potassium aluminium tetrahydride KAlH4 of high phase purity (space group Pnma
(62)) was synthesized via a mechanochemical route. The thus obtained material
was studied by 27Al and 39K MAS NMR spectroscopy. For both nuclei precise data
for the isotropic chemical shift and the quadrupole coupling at T=295 K were
derived (27Al: delta_iso=(107.6+-0.2) ppm, C_Q = (1.29+-0.02) MHz and eta =
0.64+-0.02; 39K: delta_iso=(6.1+-0.2) ppm, C_Q = (0.562+-0.005) MHz and eta =
0.74+-0.02). The straightforward NMR spectroscopic approach applied here should
also work for other complex aluminium hydrides and for many other materials
containing half-integer nuclei experiencing small to medium-sized quadrupole
couplings.
