Adaptive Resolution Simulations: Towards Open Systems Molecular
Kurt Kremer (Max
Planck Institute for Polymer Research)
The relation between atomistic structure,
architecture, molecular weight and material properties is a basic
concern of modern soft matter science. This longstanding aim by now
goes far beyond standard properties of bulk materials. A typical
additional focus is on surface interface aspects or the relation
between structure and function in nanoscopic molecular assemblies This
all implies a thorough understanding on many length and correspondingly
time scales ranging from (sub)-atomic to macroscopic. Traditionally
computer simulations have been separated in two main groups, namely
simplified models to deal with generic or universal aspects, i.e.
critical exponents, of polymers and those employing classical force
field simulations with (almost) all atomistic detail, i.e. for the
diffusion of small additives in small â€œsampleâ€. To
adaptive schemes have to be developed, which allow for a free exchange
of particles (atoms, molecules) between the different levels of
resolution. First attempts towards this direction will be presented in
this lecture. We study model systems, which display a spatially
variable resolution with a free exchange of particles between the
different regimes, ranging from atomistic resolution to coarse grained
The new scheme can be understood within a (very limited analogy) to
a geometry induced phase transition, where in the transition regime
degrees of freedom are switched on or off. Theoretically one can
formulate this in terms of fractional degrees of freedom. This
methodology has been tested for methane like tetrahedral liquids,
polymers in solution as well as liquid water.
M. Praprotnik, L. Delles Site, K. Kremer â€žAdaptive Resolution
Molecular Dynamics Simulation: Changing the Degrees of Freedom on the
Flyâ€ J. Chem. Phys. *123 *(2005)
M. Praprotnik, S. Matysiak, L.
Delle Site, K. Kremer, C. Clementi, Adaptive Resolution Simulation of
Liquid Waterâ€œ, J. Phys. Cond. Matt. *19,* 292201 (2007)
N.F.A. van der Vegt, C. Peter, and K. Kremer, Structure-based coarse-
and fine-graining in soft matter simulations, In Coarse-Graining of
Condensed Phase and Biomolecular Systems, ed. G.A. Voth, Chapman and
Hall/CRC Press, Taylor and Francis Group, 2008
M. Praprotnik, L. Delle Site, and K. Kremer, Multiscale Simulation of
Soft Matter: From Scale Bridging to Adaptive Resolution, Annu. Rev.
Phys. Chem. *59*, (2008).