We analyze the electronic structure of the Os(0001) surface by means of first principle calculations based on fully relativistic density functional theory and a PAW approach. 
We investigate both electronic resonances and surface states analyzing the spin-orbit induced energy splitting and the
spin-polarization, and comparing with previously studied
surfaces (Ir(111), Pt(111), Au(111)). In particular we focus on L-gap surface states that, well studied in Au(111), have
been recently found to have a characteristic negative dispersion
in Ir(111). 
 A. Dal Corso, Phys. Rev. B 82, 075116 (2010).
 A. Varykhalov et al. Phys. Rev. Lett. 108, 066804 (2012).