Artigo Acesso aberto

More accurate generalized gradient approximation for solids

2006; American Physical Society; Volume: 73; Issue: 23 Linguagem: Inglês

10.1103/physrevb.73.235116

ISSN

1550-235X

Autores

Zhigang Wu, R. E. Cohen,

Tópico(s)

Superconductivity in MgB2 and Alloys

Resumo

We present a nonempirical density functional generalized gradient approximation (GGA) that gives significant improvements for lattice constants, crystal structures, and metal surface energies over the most popular Perdew-Burke-Ernzerhof (PBE) GGA. The functional is based on a diffuse radial cutoff for the exchange hole in real space, and the analytic gradient expansion of the exchange energy for small gradients. There are no adjustable parameters, the constraining conditions of PBE are maintained, and the functional is easily implemented in existing codes.

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