Fig. 3: Examples of quantum spin Hall insulators (QSHI).

Spillage (a, d, g), surface (b, e, h), and edge bandstructure (c, f, i) plots. a–c For BiI, d–f for Bi₂TeI, g–i for HfTe₅. In (c, f, i) the color scale represents the electron occupation. The Fermi energy is set to zero in all band structure plots.