Regensburg 2002 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 6: Poster: Neue Methoden

CPP 6.3: Poster

Monday, March 11, 2002, 13:30–15:00, B

A genetic algorithm for global optimization and its application to sodium chloride clusters — •Hendrik Kabrede and Reinhard Hentschke — Physics Department and Institute for Materials Science, Wuppertal University, Gauss-Strasse 20, 42097 Wuppertal, Germany

In general it is a difficult task to find the global minimum structure of an ionic (or molecular) cluster. Even for a simple pair potential which only takes the two major interaction effects into account, i.e., Coulomb interaction and the repulsion of the ion cores due to the exclusion principle at short distances, the number of local minima on the potential energy hyper-surface should be growing exponentially with increasing cluster size. Therefore a systematic search is not feasible. We have developed an algorithm with a self-guiding search strategy, using a variety of ’traditional’ genetic operators, that act on strings of real numbers, and geometric genetic operators. This still quite simple algorithm is applied successfully to the search for global minima on the potential energy hyper-surface of the most widely studied ionic clusters, sodium chloride clusters, with up to 100 ions.