OGOLEM: Global cluster structure optimisation for arbitrary mixtures of flexible molecules. A multiscaling, object-oriented approach

Abstract

In practical applications, global cluster structure optimisation has so far been limited largely to homogeneous clusters of atoms or small molecules, with little or no choice in the calculation of inter-particle forces. We eliminate these limitations by presenting a new program suite OGOLEM that is universal by design, both in cluster composition (including arbitrarily heterogeneous clusters of complicated molecules) and in its interfaces to force calculation backends. This is demonstrated by exemplary applications in two novel fields: strongly heterogeneous Lennard–Jones clusters (ternary, quaternary, quinary) and mixed clusters of the aminoglycoside Kanamycin A with sodium cations.

Keywords:

• global optimisation
• genetic algorithms
• cluster structures
• Lennard–Jones
• Kanamycin A

Acknowledgements

The authors would like to thank Prof. Dr. Hans-Joachim Werner for his generous support. The authors are also grateful to Prof. Dr. Jens-Michael Schröder for his enthusiastic initiative in starting a collaboration on KA aggregates. A large computer time grant at the HLRN supercomputer center (Berlin/Hannover) is gratefully acknowledged.