Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 84: Novel Functional Materials I
HL 84.8: Vortrag
Donnerstag, 10. März 2016, 17:15–17:30, H17
Cubic scaling GW: towards fast quasiparticle calculations — •Peitao Liu1,2, Merzuk Kaltak1, Jiri Klimeš1, and Georg Kresse1 — 1University of Vienna, Faculty of Physics and Center for Computational Materials Science, Sensengasse 8/12, A-1090 Vienna, Austria — 2Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Within the framework of the full potential projector-augmented wave (PAW) methodology, we present a promising low scaling GW implemention. It allows for quasiparticle calculations with a scaling that is cubic in the system size and linear in the number of k points used to sample the Brillouin zone. This is achieved by calculating the independent particle polarizability in real space and imaginary time via contraction over the Green’s functions of occupied and unoccupied states. The Fourier transformation of the polarizability from the imaginary time to frequency domain is done by a very efficient discrete Fourier transformation with only a few nonuniform grid points. Fast Fourier transformations are used to go from real space to reciprocal space and vice versa. The analytical continuation from the imaginary axis to the real axis is done by exploiting the Thiele’s reciprocal difference method. Finally, the method is applied successfully to predict the quasiparticle energies and spectral functions of typical semiconductors (Si, SiC, GaAs and ZnO) and metals (Na, Al, Pd, and SrVO3). The results are compared with conventional standard GW calculations. Good agreement is achieved, highlighting the power of this method.