COHESIVE AND ELECTRONIC-PROPERTIES OF ORDERED LI-AL INTERMETALLIC COMPOUNDS

Self-consistent electronic structure calculations have been performed on ordered lithium-aluminium compounds using the tight-binding linear muffin-tin orbital (TBLMTO) method. The FCC-based ground-state superst ructures (namely L1(2) and L1(0) structures) show some systematic tren ds in their cohesive and electronic properties, which are in reasonabl y good agreement with the available experimental data. We have also co mpared the density of states, band structures and total ground-state e nergies of equiatomic AlLi compounds, between the FCC-based L1(0) stru cture and the BCC-based B32 structure. While the former shows a two-di mensional metallic behaviour, the latter shows a resemblance to a tetr ahedral-bonded covalent solid, and is more stable. After detailed comp arison with some recent LAPW calculations, we conclude that the TBLMTO method can be used as an efficient and reasonably accurate first-prin ciples tool for studying the phase stability and chemical bonding in o rdered intermetallic compounds.