Beschreibung:
<jats:title>Abstract</jats:title><jats:p>A method, developed in previous papers is applied to the a priori analysis of the thermodynamical stability of the crystal structures of the compounds LiAl, TiTl, and NaTl. Allowing for only pairwise interaction (second order of the pseudopotential perturbation theory), it is found that the structure B‐2 (of CsCl type) is the most stable one for LiAl and LiTl, while in NaTl a spinodal decomposition must arise. Inclusion of multi‐ion interaction, using some higher‐order terms of the Brillouin‐Wigner perturbation theory results in a stabilization of the B‐32 structure in NaTl and LiAl while in LiTl the B‐2 structure is left stable. The structures obtained are experimentally observed. The thermodynamical evolution of the structures is also discussed.</jats:p>