Prediction of topological insulating behavior in inverse Heusler compounds from first principles

The topological band structures of the X2YZ inverse Heusler compounds have been investigated by the first-principle calculations. The results of this study clearly indicate that a large number of inverse Heusler compounds naturally exhibit an inverted band structure. We found that, similar to the half-Heusler family, these inverse Heusler compounds can realize the topological insulating state under hydrostatic or uniaxial lattice expansion. Importantly, most of these compounds possess a negative formation energy, which makes them more suitable in material growth and could easily achieve the topological insulating behavior by alloying or proper strain.