Assessing common density functional approximations for the ab initio description of monovacancies in metals

• Using the exact muffin-tin orbitals method, we investigate the accuracy of five common density functional approximations for the theoretical description of the formation energy of monovacancies in three close-packed metals. Besides the local density approximation (LDA), we consider two generalized gradient approximation developed by Perdew and co-workers (PBE and PBEsol) and two gradient-level functionals obtained within the subsystem functional approach (AM05 and LAG). As test cases, we select aluminum, nickel, and copper, all of them adopting the face centered cubic crystallographic structure. Our results show that, compared to the recommended experimental values, LDA is be the most reliable approximation for the vacancy formation energies in these metals. However, taking into account also the performances of the functionals for the equation of state changes the final verdict in favor of the generalized gradient approximations.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

vacancy-formation energies

electron-gas

1st-principles calculations

transition-metals

aluminum

fcc

fe

impurities

perovskite

alloys

Physics

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)