First-principles calculations of the band ordering conversion in the LaxSc2−xRuPb compounds

Topological insulators (Tls) are new kinds of quantum's materials states discovered recently, with insulating bulk band gaps and topologically protected metallic surface states; they are immensely investigated due to their promising characteristics for spintronic and quantum computing applications. In this work, we study the potential of Tl property in inverses Heusler compounds (LaxSc2−xRuPb) with x = 0, 1 and 2, by first-principles calculations within the full-potential linear muffin-tin orbital (FP-LMTO) computational approach method as implemented in the computer code (LMTART), which is based on the density functional theory (DFT). We used the local-density approximation (LDA) for the term of the exchange and correlation potential (XC). We investigate the topological ordering of quaternary inverse Heusler XX'YZ according to the possible X and X′ sites combination, and we focus that the trivial semiconductors compounds in x = 0, 2 with the positive energy difference (ΔE=EΓ6−EΓ8) exhibit a non trivial candidates in x = 1 with EΓ6−EΓ8<0.