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Surface energies of simple metals from slabs: A comparison of exchange-correlation density functionals

Authors: Carlos Fiolhais and L. M. Almeida

Ref.: International Journal of Quantum Chemistry 101, 645-650 (2005)

Abstract: Surface energies of some simple metals (Be, Al, Mg, Li, and Na) were calculated within density functional theory. Various approximations for the exchange and correlation were tested: Local Density Approximation (LDA), Generalized Gradient Approximations (GGA) and Meta Generalized Gradient Approximation (MGGA). We used the CRYSTAL98 code to calculate slabs with 1 to 10 layers using both all-electron and pseudopotential approaches. The extraction of the surface energy from the series of slab energies was done by the linear fitting method. Our LDA and GGA results agree reasonably well with those from other authors. MGGA values are in general close to LDA and higher than GGA ones, a pattern which is also observed in the jellium model. They also agree reasonably well with the experimental data.