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MM: Fachverband Metall- und Materialphysik

MM 12: Poster I

MM 12.17: Poster

Montag, 27. März 2023, 18:15–20:00, P2/OG1+2

A method for charge-sloshing free precise linear-scaling density-functional calculations — •Rudolf Zeller — Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany

A fundamental problem for large-scale density-functional calculations is charge sloshing caused by the long-ranged Coulomb potential which necessitates that the number of self-consistency steps increases proportionally to the square of system length. To overcome this problem, Manninen et al. (1975) used a screened Coulomb potential to devise a real-space potential-mixing scheme which in reciprocal space is well-known as Kerker mixing.

It will be described how (1) this scheme works in the linear-scaling real-space code KKRnano which is part of the JuKKR code family developed at the reasearch center Jülich, how (2) it can be turned into a real-space preconditioning method for potential mixing and how (3) it can be refined for excellent numerical performance.

Benchmark calculations will be presented for spin-orbit induced noncollinear magnetism in B20 MnGe and for a vacancy in Cu. It will be shown that the computing effort is drastically reduced, that the number of self-consistency steps does not increase with system size and that precise total-energy differences can be obtained even for supercells with more than 100000 atoms.

It should be noted that the method presented does not rely on using linear response or properties of the static dielectric matrix.