Asymptotics of the metal-surface Kohn-Sham exact exchange potential revisited

Abstract

The asymptotics of the Kohn-Sham (KS) exact exchange potential of a jelliumlike semi-infinite metal is investigated in the framework of the optimized-effective-potential formalism of density-functional theory. Our numerical calculations clearly show that deep into the vacuum side of the surface with being a system-dependent constant, thus, confirming the analytical calculations reported in Phys. Rev. B81, 121106(R) (2010)PRBMDO1098-012110.1103/PhysRevB.81.121106. A criticism of this work published in Phys. Rev. B85, 115124 (2012)PRBMDO1098-012110.1103/PhysRevB.85.115124 is shown to be incorrect. Our rigorous exchange-only results provide strong constraints both for the building of approximate exchange functionals and for the determination of the still unknown KS correlation potential.