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MA: Fachverband Magnetismus

MA 12: Magnetic Particles/ Clusters II

MA 12.6: Vortrag

Montag, 14. März 2011, 18:15–18:30, HSZ 103

Ab initio energy landscapes including spin degrees of freedom — •Luis Enrique Diaz Sanchez, Junais Habeeb Mokkath, and Gustavo Pastor — Institut fuer theoretische physik, Universitaet Kassel, Heinrich Plett. Str. 40, 34132 Kassel, Germany

In this work we present a systematic performance analysis of spin-polarized-first-principles (SPFP) basin-hopping (BH) calculations. The global search and local minima are calculated in the framework of spin-polarized density functional theory within the generalized gradient approximation. This formalism allow us to identify not only low-energy isomers but also their respective magnetic properties. In order to explore the configuration space collective (or shake) moves and are employed. different magnitude of random displacements are considered. The variation of the magnitude of the random displacements permit us to modulate the jumps into the different minima in the potential energy surface. Results for different initial configuration are presented: initial random-clusters created in the spirit of the big-bang method, present well know ground states geometries and configurations in which the atoms are also randomly large separated at the beginning. We will show that choosing a correct sett of move parameters the performance of the SPFP-BH is very good for small nanoalloys and that considering additional spin degrees of freedom it is possible to predict not only the most stable structural motifs, as it happens with the standard BH technique, but also isomers having different magnetic moments for the case of small FeCo composomers.