Materials and Molecular Modeling (M&MM)

“If you want to study function, study structure” - Francis Crick

Leader: Jaakko Akola (Academy Research Fellow, Ph.D.)

Recent developments in computers and computational algorithms have made it possible to study electronic structure and dynamics of systems with up to several thousand atoms and on picosecond time scales. Moreover, methods using classical force fields (i.e., neglecting the detailed electronic structure) expand both time and length scales to allow microsecond simulations of systems consisting up to 100 000 atoms and more. This means that high-accuracy simulations are now possible to support the experimental work done with materials science (alloys, surfaces), nanodevices (nanotubes, nanowires, nanodots), biomolecules (proteins, enzymes, pharmaceuticals), as well as with macromolecules important in chemical industry (polymers, dendrimers, supermolecules). A remaining challenge is to identify the right method and machinery for a specific problem, so that scientifically meaningful simulations can be performed in a reasonable time.

The M&MM group performs massively-parallel simulations of materials and biomolecules at the atomistic scale using both electronic structure calculations (DFT) and classical molecular mechanics (MM). The general objective our research is to study the detailed atomic structure of a system and its function. The problems involve current technological applications in the fields of materials science, chemistry, and biochemistry. Currently, the main topics are:

Amorphous semiconductor materials, especially chalcogenides (DVD-RAM, DVD-RW, Blu-ray Disc, Phase-change RAM, Conductive-bridging RAM)
Noble metal nanoparticles (Au, Ag, Pd) and chalcogenide nanocystals/particles
ATP-binding integral membrane proteins (e.g. ABC transporters) and ATP hydrolysis

Our projects are highly ambitious in terms of computing power, but we have access to one of the World’s most powerful supercomputers - IBM Blue Gene/P in the Research Center Jülich (Forschungszentrum Jülich, Germany) – where our projects have a “Grand Challenge” status. Part of the simulations are being performed on the national supercomputers at CSC, Espoo.

Old group page: http://iffwww.iff.kfa-juelich.de/~jeakola/J.Akola.shtml

HOST ORGANIZER OF

European\Phase Change and Ovonics Symposium 2012

http://www.epcos.org/EPCOS2012/epcos2012Symposium.htm

Recent highlights:

E. Heikkilä, A. A. Gurtovenko, H. Martinez-Seara, H. Häkkinen, I. Vattulainen, and J. Akola, Atomistic Simulations of Functional Au₁₄₄(SR)₆₀ Gold Nanoparticles in Aqueous Environment, J. Phys. Chem. C 116, 9805 (2012) | doi:10.1021/jp301094m
S. Kohara, J. Akola, H. Morita, K. Suzuya, J. K. R. Weber, M. C. Wilding, and C. J. Benmore, Relationship between topological order and glass forming ability in densely packed enstatite and forsterite composition glasses , Proc. Natl. Acad. Sci. U.S.A. 108, 14780 (2011) | doi:10.1073/pnas.1104692108
T. Matsunaga, J. Akola, S. Kohara, T. Honma, K. Kobayashi, E. Ikenaga, R.O. Jones, N. Yamada, M. Takata, and R. Kojima, From local structure to nanosecond recrystallization dynamics in AgInSbTe phase-change materials, Nature Materials 10, 129 (2011) | doi:10.1038/nmat2931
O. Lopez-Acevedo, K.A. Kacprzak, J. Akola, and H. Häkkinen, Quantum size effects in ambient CO oxidation catalysed by ligand-protected gold clusters, Nature Chemistry 2, 329 (2010) | doi:10.1038/nchem.589