The application of evolution strategies to disordered structures

Evolution strategies are applied to refine structural fragments, like molecules or complex anions, of orientationally disordered crystals. Optimal geometric embedding of the fragments into electron density distributions, resulting from maximum-entropy (ME) reconstructions, are performed. The evolution paradigm is found to be also applicable for the refinement against structure factors, for which the structural model is carefully selected from the ME densities. Suitably modified, the method is used successfully to compute reorientation pathways and to predict disordered high-pressure configurations in a non-classical qualitative model.