Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 50: Poster II
HL 50.59: Poster
Donnerstag, 30. März 2006, 16:30–19:00, P3
An all-Electron GW Code Based on FP-(L)APW+lo — •Ricardo I. Gomez-Abal, Xinzheng Li, and Matthias Scheffler — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin.
In recent years the GW approximation (GWA), typically applied as perturbation to DFT, has proven to be very successful describing quasi-particle excitations in semiconductors and insulators. Most of the existing codes are based on the pseudopotential (PP) method, which is well established for ground state DFT calculations. In this scheme, the self energy is computed for the valence states only. There is, however, no guarantee that “core-valence partitioning” done in this fashion is justified for the dynamical self energy, which is a highly non-linear functional of the total density. G0W0 results obtained with PP implentations are usually in better agreement with experiments than those reported from existing all-electron implementations. Self-consistent schemes improve the agreement of the all-electron calculations [1], but drastically worsen the PP results [2]. The reasons for this discrepancy and the necessity for self-consistency are still a matter of debate [1,2]. In order to address these questions, we are developing our own all-electron GW code. It is based on the FP-(L)APW+lo method, which currently provides the most reliable results within DFT. The code treats core, semicore and valence states on the same footing, which implies that it is applicable to a wide range of materials. In this poster we present a description of the code and the first results obtained for silicon.
[1] W. Ku and A. G. Eguiluz, Phys. Rev. Lett. 89, 126401 (2002).
[2] K. Delaney, et al. Phys. Rev. Lett. 93, 249701 (2004).