Asymptotic form of the Kohn-Sham correlation potential

摘要

The density-functional correlation potential of a finite system is shown to asymptotically approach a nonzero constant along a nodal surface of the energetically highest occupied orbital and zero everywhere else. This nonuniform asymptotic form of the correlation potential exactly cancels the nonuniform asymptotic behavior of the exact exchange potential discussed by Della Sala and Gorling [Phys. Rev. Lett. 89, 33003 (2002)]. The sum of the exchange and correlation potentials therefore asymptotically tends to -1/r everywhere, consistent with the asymptotic form of the Kohn-Sham potential as analyzed by Almbladh and von Barth [Phys. Rev. B 31, 3231 (1985)].