Fig. . Electronic band structure (a, c) and DOS (b, d) of RbBi2 and CsBi2 respectively, calculated in a scalar-(without SOC; red line) and fully relativistic approach (with SOC; black). Panels (e) and (f) show the band structure around the Brillouin zone center (Γ) for RbBi2. At the X point the degeneracy is symmetryprotected, so the inclusion of SOC results only in shifting the band energies (points marked with green rectangles), while at L-point they are additionally split (purple rectangles).