  In this paper, by first principle calculations, we investigate systematically
the band topology of a new half-Heusler family with composition of
I(A)-III(A)-IV(A). The results clearly show that many of the I-III-IV
half-Heusler compounds are in fact promising to be topological insulator
candidates. The characteristic feature of these new topological insulators is
the naturally strong band inversion strength (up to -2eV) without containing
heavy elements. Moreover, we found that both the band inversion strength and
the topological insulating gap can be tailored through strain engineering, and
therefore would be grown epitaxially in the form of films, and useful in
spintronics and other applications.
