Hexagonal ABC polar metals from first principles

Ternary ABC intermetallic compounds exhibit a rich variety of crystal structures and electronic properties. In this work, we study the structural energetics and band structures of real and hypothetical hexagonal ABC intermetallic phases, using first principles calculations to determine the structural parameters and the bands in each phase. We use this dataset to analyze and model the bands near the Fermi level in metallic examples to classify the systems considered and to connect to experimental measurements on known hexagonal ABC phases. The possibility of switchability of the polar distortion in these polar metals by appropriate applied fields and stresses offers the promise of functional optical and transport properties, with examples to be discussed.