Organisers

• Matous Mrovec (Fraunhofer Institute for Mechanics of Materials, Freiburg, Germany)
• Peter Derlet (Paul Scherrer Institut, Villigen, Switzerland)

Supports

   CECAM

Description

Much of the atomistic modeling being undertaken still uses either simple central-force models of interatomic interactions, e.g., the embedded-atom method or Finnis-Sinclair potentials, or models which include angular interactions in the most simple or ad hoc way. Such models typically constitute considerable simplifications of the underlying quantum mechanics and as a result often fail to reproduce the structures and energetics of even the most basic lattice defects. This somewhat disparaging situation makes it difficult to gain confidence in the predictive capabilities of empirical atomistic calculations, particularly when the results are used as microscopic input to higher length- and time-scale modeling methods; a regime which can give fundamentally different results when input energies might vary by only a few tenths of eV.

Scientific Objectives

In the proposed workshop, we would like to address the development of interatomic potentials for transition metals and their compounds on a broader scale. We would like to bring together experts developing empirical potentials with those specialized in quantum mechanical methods. We believe that the mutual interaction will be very valuable and will contribute tremendously to the further development of leading-edge interatomic potentials, especially in terms of transferability and theoretical justification.

In particular, the workshop will focus on the following issues:

• Optimal balance between simplicity and quality of an empirical potential.

• Given that truly reliable and transferable empirical potentials still do not exist –even for elemental materials – is a fundamental theoretical understanding still lacking?

• Complications when going from single elements to compounds. 

• The nature of repulsive potential – does a systematic approach really exist?

• Long-range central-force potentials versus explicit angular terms.

• Inclusion of magnetism and charge transfer effects.

References

• M. Finnis, Interatomic Forces In Condensed Matter, Oxford University Press, 2003.
• D. G. Pettifor, Bonding and Structure of Molecules and Solids, Oxford University Press, 1995.
• Philosophical Magazine (Special issue on Finnis-Sinclair potentials) 2009.
• Progress in Materials Science 52, Numbers 2-3 (2007) “Modelling electrons and atoms for materials science”
• S. L. Dudarev, J. -L. Boutard, R. Lässer, M. J. Caturla, P. M. Derlet, M. Fivel, C.-C. Fu, M. Y. Lavrentiev, L. Malerba, M. Mrovec, D. Nguyen-Manh, K. Nordlund, M. Perlado, R. Schäublin, H. Van Swygenhoven, D. Terentyev, J. Wallenius, D. Weygand and F. Willaime, “The EU programme for modelling radiation effects in fusion reactor materials: An overview of recent advances and future goals”, J. Nucl. Instr. Meths, 386-388, 1 (2009).
• M. Mrovec et al., Phys. Rev. B, 69, 94115 (2004).
• C. Goringe, D. Bowler, and E. Hernandez, Rep. Prog. Phys. 60, 1447 (1997).
• Horsfield, A. Bratkovsky, D. Pettifor, and M. Aoki, Phys. Rev. B 53, 1656 (1996).
• M. S. Daw and M. I. Baskes, Phys. Rev. Lett. 50, 1285 (1983).
• M. S. Daw and M. I. Baskes, Phys. Rev. B 29, 6443 (1984).
• M. W. Finnis and J. E. Sinclair, Phil. Mag. A 50, 45 (1984).
• A. P. Sutton, M. W. Finnis, D. G. Pettifor, and Y. Ohta, J. Phys. C: Solid State 21, 35 (1988).
• S. Dudarev and P. M. Derlet, “A ‘magnetic’ interatomic potential for molecular dynamics simulations.”, J. Phys.: Cond. Matt., 17, 7097 (2005).