First-principles investigation of the structural, elastic, and electronic properties of Half-Heusler compounds LiTiB and LiTiAl

This study presents a first-principles investigation based on density functional theory (GGA) of the Half-Heusler compounds LiTiB and LiTiAl. Structural stability was evaluated through total energy optimization of three possible atomic configurations, with the Type-II phase identified as the energetically most favorable. Mechanical stability is confirmed by the calculated elastic constants, which satisfy the Born stability criteria. The derived mechanical parameters indicate that LiTiAl exhibits greater ductility, whereas LiTiB demonstrates higher stiffness. Both compounds exhibit metallic behavior, as evidenced by their electronic band structures and density of states. The electronic states near the Fermi level are predominantly governed by Ti d-states, while contributions from B p- or Al p-states are minor, and Li shows negligible participation. These findings indicate that LiTiB and LiTiAl are structurally stable and mechanically robust Half-Heusler metallic alloys with potential relevance for structural and functional applications.