Cubic scaling $GW$: towards fast quasiparticle calculations
Abstract
Within the framework of the full potential projector-augmented wave methodology, we present a promising low-scaling implementation. It allows for quasiparticle calculations with a scaling that is cubic in the system size and linear in the number of points used to sample the Brillouin zone. This is achieved by calculating the polarizability and self-energy in the real space and imaginary time domain. The transformation from the imaginary time to the frequency domain is done by an 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 analytic continuation from the imaginary to the real frequency axis is performed by exploiting Thiele's reciprocal difference approach. Finally, the method is applied successfully to predict the quasiparticle energies and spectral functions of typical semiconductors (Si, GaAs, SiC, and ZnO), insulators (C, BN, MgO, and LiF), and metals (Cu and SrVO). The results are compared with conventional calculations. Good agreement is achieved, highlighting the strength of the present method.
Keywords
Cite
@article{arxiv.1607.02859,
title = {Cubic scaling $GW$: towards fast quasiparticle calculations},
author = {Peitao Liu and Merzuk Kaltak and Jiří Klimeš and Georg Kresse},
journal= {arXiv preprint arXiv:1607.02859},
year = {2016}
}