Effect of spatial nonlocality on the density functional band gap

Myrta Gruning, Andrea Marini, Angel Rubio

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)

Abstract

We show that for a large class of exchange-correlation functionals the local exchange-correlation potential obtained within an optimized effective potential severely underestimates the band gap. On the other hand, the corresponding nonlocal potential obtained from a generalized Kohn-Sham scheme provides a much better description of the band gap, in good agreement with experiments. These results strongly indicate that a local exchange-correlation potential, however good the exchange-correlation approximation, cannot capture the delicate interplay between correlation effects and spatial localization in the KS band structure, unless the (cumbersome) contribution from the derivative discontinuity of the exchange-correlation energy functional is considered.

Original languageEnglish
Article number161103
Pages (from-to)-
Number of pages4
JournalPhysical Review B (Condensed Matter)
Volume74
Issue number16
DOIs
Publication statusPublished - Oct 2006

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