  We performed first-principles density functional theory (DFT) and GW
calculations to investigate electronic structures of bulk and few-layer PdSe2.
We obtained the quasiparticle band structure of bulk PdSe2, and the obtained
energy gap agrees excellently with the reported experimental value. For
monolayer and bilayer PdSe2, we obtained quasiparticle band structures with
respect to the vacuum level. We analyzed DFT and GW band structures in detail,
finding k-space positions of valence band maxima and conduction band minima,
effective masses, the quasiparticle density of states, work functions,
ionization potentials, electron affinities, and k-space shapes of electron and
hole pockets. These results provide a foundation for development of basic
studies and device applications.
