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Title: Communication: A new paradigm for structure prediction in multicomponent systems

We analyse the combinatorial aspect of global optimisation for multicomponent systems, which involves searching for the optimal chemical ordering by permuting particles corresponding to different species. The overall composition is presumed fixed, and the geometry is relaxed after each permutation in order to relieve local strain. From ideas used to solve graph partitioning problems we devise a deterministic search scheme that outperforms (by orders of magnitude) conventional and self-guided basin-hopping global optimisation. The search is guided by the energy gain from either swapping particles i and j (ΔE{sub ij}) or changing the identity of particles i (ΔE{sub i}). These quantities are derived from the underlying (arbitrary) energy function, hence not constituting external bias, and for site-separable force fields each ΔE{sub i} can be approximated simply and efficiently. In our self-guided variant of basin-hopping, particles are weighted by an approximate ΔE{sub i} when randomly selected for an exchange, yielding a significant improvement for segregated multicomponent systems with modest particle size mismatch.
Authors:
;  [1]
  1. University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW (United Kingdom)
Publication Date:
OSTI Identifier:
22253840
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; APPROXIMATIONS; PARTICLE SIZE; PARTICLES