Regensburg 2010 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 52: Electronic Properties II
MM 52.5: Vortrag
Donnerstag, 25. März 2010, 12:30–12:45, H5
Efficient and accurate method for calculating properties of random alloys with short-range order — •Oleg Peil1, Andrei Ruban2, and Börje Johansson2 — 1I. Institut für Theoretische Physik, Universität Hamburg — 2Department of Materials Science, Royal Institute of Technology, Sweden
We present an efficient and accurate method for calculating properties of alloys with short-range order. The method is based on the Green’s function approach in the framework of the exact muffin-tin orbital (EMTO) [1] fomralism. An alloy system is represented by a supercell with short-range order parameters controlled up to high coordination sphere numbers (4-10), and the local Green’s function of each atom is calculated exactly within the local interaction zone (LIZ). The key ingredients of the method are locality, which makes it linearly-scaling with the number of atoms in the supercell, and self-consistency of the effective medium, which results in fast convergence of the total energy and density of states with respect to the LIZ size.
To test the performance and accuracy of the developed method, we show by several examples that for ordered alloys it correctly reproduces the density of states and total energy for both the single-site limit (LIZ=1) and ordered limit (LIZ→∞). The method is then applied to two systems: Fe2Si and Fe-rich bcc-FeCr that have a strong dependence of the local magnetic moments and interatomic interactions on the local environment.
[1] L. Vitos, Phys. Rev. B 64, 014107 (2001)