Boosting the efficiency of ab initio electron-phonon coupling calculations through dual interpolation

TL;DR

This paper introduces a dual interpolation method combining Wannier functions and symmetry-adapted plane waves to significantly accelerate ab initio electron-phonon coupling calculations, enabling more efficient transport property predictions.

Contribution

The authors develop a novel dual interpolation technique that greatly improves the computational efficiency of electron-phonon coupling calculations compared to existing methods.

Findings

Performance gain of approximately 2n_s  M over Wannier-Fourier interpolation.

Method successfully applied to several ab initio electron-phonon interaction calculations.

Demonstrates potential for faster and more efficient transport property simulations.

Abstract

The coupling between electrons and phonons in solids plays a central role in describing many phenomena, including superconductivity and thermoelecric transport. Calculations of this coupling are exceedingly demanding as they necessitate integrations over both the electron and phonon momenta, both of which span the Brillouin zone of the crystal, independently. We present here an ab initio method for efficiently calculating electron-phonon mediated transport properties by dramatically accelerating the computation of the double integrals with a dual interpolation technique that combines maximally localized Wannier functions with symmetry-adapted plane waves. The performance gain in relation to the current state-of-the-art Wannier-Fourier interpolation is approximately 2n_s \times M, where n_s is the number of crystal symmetry operations and M, a number in the range 5 - 60, governs the expansion in star functions. We demonstrate with several examples how our method performs some ab initio calculations involving electron-phonon interactions.