Fully-relativistic full-potential multiple scattering theory: A pathology-free scheme

Xianglin Liu, Yang Wang, Markus Eisenbach, G. Malcolm Stocks

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

The Green function plays an essential role in the Korringa–Kohn–Rostoker(KKR) multiple scattering method. In practice, it is constructed from the regular and irregular solutions of the local Kohn–Sham equation and robust methods exist for spherical potentials. However, when applied to a non-spherical potential, numerical errors from the irregular solutions give rise to pathological behaviors of the charge density at small radius. Here we present a full-potential implementation of the fully-relativistic KKR method to perform ab initio self-consistent calculation by directly solving the Dirac differential equations using the generalized variable phase (sine and cosine matrices) formalism Liu et al. (2016). The pathology around the origin is completely eliminated by carrying out the energy integration of the single-site Green function along the real axis. By using an efficient pole-searching technique to identify the zeros of the well-behaved Jost matrices, we demonstrated that this scheme is numerically stable and computationally efficient, with speed comparable to the conventional contour energy integration method, while free of the pathology problem of the charge density. As an application, this method is utilized to investigate the crystal structures of polonium and their bulk properties, which is challenging for a conventional real-energy scheme. The noble metals are also calculated, both as a test of our method and to study the relativistic effects.

Original languageEnglish
Pages (from-to)265-272
Number of pages8
JournalComputer Physics Communications
Volume224
DOIs
StatePublished - Mar 2018

Funding

This manuscript has been co-authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This work was sponsored by the U.S. Department of Energy , Office of Science , Basic Energy Sciences , Material Sciences and Technology Division . This research used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575 . Specifically, it used the Bridges system, which is supported by National Science Foundation (NSF) award number ACI-1445606 , at the Pittsburgh Supercomputing Center (PSC). This research also used the resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract No. DE-AC05-00OR22725 .

Keywords

  • Dirac equation
  • Full-potential
  • Green function
  • KKR method
  • Multiple scattering theory
  • Pole-searching

Fingerprint

Dive into the research topics of 'Fully-relativistic full-potential multiple scattering theory: A pathology-free scheme'. Together they form a unique fingerprint.

Cite this