Self-consistent supercell approach to alloys with local environment effects
2012 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 85, no 16, 165140- p.Article in journal (Refereed) Published
We present an efficient and accurate method for calculating electronic structure and related properties of random alloys with a proper treatment of local environment effects. The method is a generalization of the locally self-consistent Green's-function technique for the exact muffin-tin orbital method. An alloy system in the calculations is represented by a supercell with a certain set of atomic-distribution correlation functions. The Green's function for each atom in the supercell is obtained by embedding the cluster of neighboring atoms lying within a local interaction zone (LIZ) into an effective medium and solving the cluster Dyson equation exactly. The key ingredients of the method are locality, which makes it linearly scaling with the number of atoms in the supercell, and coherent-potential self-consistency of the effective medium, which results in a fast convergence of the electronic structure with respect to the LIZ size. To test the performance and accuracy of the method, we apply it to two systems: Fe-rich bcc-FeCr random alloy with and without a short-range order, and a Cr impurity on the Fe surface. Both cases demonstrate the importance of taking into account the local environment effects for correct description of magnetic and bulk properties.
Place, publisher, year, edition, pages
2012. Vol. 85, no 16, 165140- p.
Electronic-Structure Calculations, Transition-Metal Alloys, Augmented-Wave Method, Disordered Alloys, Substitutional Alloys, Surface Segregation, Potential Model, Approximation, Systems, Representation
IdentifiersURN: urn:nbn:se:kth:diva-95253DOI: 10.1103/PhysRevB.85.165140ISI: 000303169100001ScopusID: 2-s2.0-84860259134OAI: oai:DiVA.org:kth-95253DiVA: diva2:527497
FunderSwedish Research CouncilEU, European Research Council
QC 201205212012-05-212012-05-212012-05-21Bibliographically approved