Figure 2.

(a) FeSe crystal structure; (b) full relativistic DFT calculations for the tetragonal and orthorhombic phases of FeSe (c) zoomed-in view of the DFT calculations close to the BZ corner; (d) same as in panel c, but without tetragonal phase to simulate photoemission signal; (e,f) ARPES data along the Γ–M direction in vicinity of the BZ corner taken at 6.4 K and using 42 eV and 28 eV photon energy, respectively; (g) EDCs at the BZ corner obtained by integration within 0.06 Å⁻¹ of ARPES data at panel (e,f) correspondingly.