Topological insulating characteristic in half-Heusler compounds composed of light elements

• A family of TIs composed of light elements was reported.
• The new TIs exhibit a great band inversion strength.
• SOC effect is unessential to open the insulating gap and inverse the band order.
• The band inversion and the insulating gap can occur as long as a strain is applied.

The band topology of a new half-Heusler family with 8 valence electrons composed of light elements is investigated by the first-principle calculations. Many of these compounds are predicted to be topological insulators. The new topological insulators exhibit great band inversion strength (up to −2.56 eV−2.56 eV). Both the occurrence of the band inversion and the opening topological insulating gap can be performed only by the strain engineering. Based on these results, we also argue that the spin–orbit coupling effect is not an essential factor in the band inversion and the formation of topological insulating gap.