Dresden 2011 – scientific programme

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O: Fachverband Oberflächenphysik

O 36: Poster Session II (Metals; Nanostructures at surfaces; Surface or interface magnetism; Spin-Orbit Interaction at Surfaces; Electron and spin dynamics; Surface dynamics; Methods; Theory and computation of electronic structure)

O 36.121: Poster

Tuesday, March 15, 2011, 18:30–22:00, P4

Electronic structure calculations on 100,000 atoms — •Gerald Jordan, Martijn Marsman, and Georg Kresse — University of Vienna, Faculty of Physics, and Center for Computational Materials Science, Sensengasse 8/12, A-1090 Wien, Austria

We present an efficient method for tackling electronic structure calculations on the scale of 100,000 atoms, where a full diagonalization of the Kohn-Sham Hamiltonian becomes computationally unfeasible because of cubic scaling with system size. In many applications, however, one is only interested in a few states near the Fermi level. Solving the associated interior eigenvalue problem is numerically difficult and requires a realistic model of the electronic charge density.

Our approach is based on the Jacobi-Davidson method using harmonic Ritz values, which mimicks the shift-and-invert strategy to target a specific energy but avoids any explicit inversion. In contrast to the folded spectrum technique, our method easily extends to the generalized eigenvalue problems arising from the use of pseudopotentials. To construct suitable charge densities reproducing the band structure, we fit atomic charge distributions to a self-consistent reference calculation.