This title appears in the Scientific Report :
2010
Please use the identifier:
http://dx.doi.org/10.1103/PhysRevB.81.125102 in citations.
Please use the identifier: http://hdl.handle.net/2128/10998 in citations.
Efficient implementation of the GW approximation within the all-electron FLAPW method
Efficient implementation of the GW approximation within the all-electron FLAPW method
We present an implementation of the GW approximation for the electronic self-energy within the full-potential linearized augmented-plane-wave (FLAPW) method. The algorithm uses an all-electron mixed product basis for the representation of response matrices and related quantities. This basis is deriv...
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Personal Name(s): | Friedrich, C. |
---|---|
Blügel, S. / Schindlmayr, A. | |
Contributing Institute: |
Quanten-Theorie der Materialien; IFF-1 Jülich Aachen Research Alliance - High-Performance Computing; JARA-HPC JARA-FIT; JARA-FIT Quanten-Theorie der Materialien; IAS-1 |
Published in: | Physical Review B Physical review / B, 81 81 (2010 2010) 12 12, S. 125102 125102 |
Imprint: |
College Park, Md.
APS
2010
|
Physical Description: |
125102 |
DOI: |
10.1103/PhysRevB.81.125102 |
Document Type: |
Journal Article |
Research Program: |
Grundlagen für zukünftige Informationstechnologien |
Series Title: |
Physical Review B
81 |
Subject (ZB): | |
Link: |
Get full text OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/10998 in citations.
We present an implementation of the GW approximation for the electronic self-energy within the full-potential linearized augmented-plane-wave (FLAPW) method. The algorithm uses an all-electron mixed product basis for the representation of response matrices and related quantities. This basis is derived from the FLAPW basis and is exact for wave-function products. The correlation part of the self-energy is calculated on the imaginary-frequency axis with a subsequent analytic continuation to the real axis. As an alternative we can perform the frequency convolution of the Green function G and the dynamically screened Coulomb interaction W explicitly by a contour integration. The singularity of the bare and screened interaction potentials gives rise to a numerically important self-energy contribution, which we treat analytically to achieve good convergence with respect to the k-point sampling. As numerical realizations of the GW approximation typically suffer from the high computational expense required for the evaluation of the nonlocal and frequency-dependent self-energy, we demonstrate how the algorithm can be made very efficient by exploiting spatial and time-reversal symmetry as well as by applying an optimization of the mixed product basis that retains only the numerically important contributions of the electron-electron interaction. This optimization step reduces the basis size without compromising the accuracy and accelerates the code considerably. Furthermore, we demonstrate that one can employ an extrapolar approximation for high-lying states to reduce the number of empty states that must be taken into account explicitly in the construction of the polarization function and the self-energy. We show convergence tests, CPU timings, and results for prototype semiconductors and insulators as well as ferromagnetic nickel. |