Figure 3.

a) The electronic band structures along k‐paths Г‐H‐P under different strains (namely without strain (i), and 0.5% strain along [111], [100], [110] directions (ii‐iv), respectively) for electride C12A7:4e⁻. These crossing points show six‐, four‐(Dirac), two‐fold (Weyl) and topological insulator, respectively. b) The surface states (i‐iv) corresponding to six‐, Dirac, Weyl fermions and topological insulator, where the red lines represent the Fermi arcs (six‐, Dirac‐, Weyl‐fermions) and Dirac cone (Topological insulator) surface states. c) The quantitative relationship between band degeneracy of different fermions and DOSs near the Fermi level on the (001) surface.