Physics – Condensed Matter – Materials Science
Scientific paper
2010-03-02
Physical Review B 81, 195117 (2010)
Physics
Condensed Matter
Materials Science
15 pages, 6 figures, 2 tables
Scientific paper
10.1103/PhysRevB.81.195117
We present an efficient implementation of the PBE0 hybrid functional within the full-potential linearized augmented-plane-wave (FLAPW) method. The Hartree-Fock exchange term, which is a central ingredient of hybrid functionals, gives rise to a computationally expensive nonlocal potential in the one-particle Schroedinger equation. The matrix elements of this exchange potential are calculated with the help of an auxiliary basis that is constructed from products of FLAPW basis functions. By representing the Coulomb interaction in this basis the nonlocal exchange term becomes a Brillouin-zone (BZ) sum over vector-matrix-vector products. We show that the Coulomb matrix can be made sparse by a suitable unitary transformation of the auxiliary basis, which accelerates the computation of the vector-matrix-vector products considerably. Additionally, we exploit spatial and time-reversal symmetry to identify the nonvanishing exchange matrix elements in advance and to restrict the k summations for the nonlocal potential to an irreducible set of k points. Favorable convergence of the self-consistent-field cycle is achieved by a nested density-only and density-matrix iteration scheme. We discuss the convergence with respect to the parameters of our numerical scheme and show results for a variety of semiconductors and insulators, including oxide materials, where the PBE0 hybrid functional improves the band gaps and the description of localized states in comparison with the PBE functional. Furthermore, we find that in contrast to conventional local exchange-correlation functionals ferromagnetic EuO is correctly predicted to be a semiconductor.
Betzinger Markus
Blügel Stefan
Friedrich Christoph
No associations
LandOfFree
Hybrid functionals within the all-electron FLAPW method: implementation and applications of PBE0 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Hybrid functionals within the all-electron FLAPW method: implementation and applications of PBE0, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hybrid functionals within the all-electron FLAPW method: implementation and applications of PBE0 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-663614