Figure 1
From: NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds
Crystal structure and bulk electronic states of Half-Heusler R-M-Bi.
Schematic diagrams of (a) the crystal structure, (b) bulk electronic band states without SOC (denoted as W/S) and (c) with SOC, respectively. For the band structures, SOC splits the pxyz-Γ5 state into pxy-Γ8 (j = 3/2, denoted as p3/2) and pz-Γ7 (j = 1/2, denoted as p1/2) states. The SOC parameter is defined as ESOC = EΓ8 − EΓ7, where a larger ESOC shows a stronger SOC strength in system. An illustration of SOC effects on NMR chemical shifts (d–f). The SOC-split p1/2 state imposes an additional magnetic shielding to the nucleus through hyperfine interactions. The direction of shielding tensor from SOC effects can be different, depending on the nature of exchange interactions.
