Physical Principles of Multiscale Modeling, Analysis and Simulation in Soft Condensed Matter

Coordinators: Paul Atzberger, Kurt Kremer, Mark Robbins

Soft condensed matter systems, whether of biogenic or synthetic origin, often have hierarchical structure over a wide range of length scales, from atomic to molecular to mesoscopic to macroscopic.  Capturing the influence of physical processes at all of these scales in a unified model poses a major theoretical challenge, particularly given that characteristic times grow with length scale.  There has been great interest and activity in the development of multiscale methods to address this challenge.  These methods attempt to bridge scales by coupling descriptions with different spatial and temporal resolution. In many cases, the physical descriptions must also vary with scale, ranging from quantum mechanical treatment of electrons or protons at atomic scales, to motion of discrete atoms, molecules or groups of molecules at intermediate scales, to mesoscopic or continuum treatments at larger scales. 

Development of multiscale methods has in general proceeded rather independently in the physics, chemistry, and applied mathematics communities.  Approaches have varied from ad hoc fitting procedures designed to make contact with specific experimental systems to studies of simple low-dimensional models or models with few degrees of freedom that are amenable to analytic analysis.  This research program will bring together researchers from a wide range of backgrounds for an extended period of communication and collaboration on the theoretical foundations of multiscale methods, to rigorously refine how they are used, and to broaden their applicability. The ultimate goal is to work towards a framework for multiscale modeling that is on the same firm footing as renormalization group methods or the approaches of computational statistical mechanics. 

To obtain a focused emphasis, we shall primarily emphasize applications to soft condensed matter systems, but include key work on methods with broader applicability.  Both major classes of multiscale modeling approaches will be included: hierarchical coupling of descriptions at different scales and simultaneous solutions of problems with different resolutions in different, temporally variable spatial regions.  Central themes of the workshop will include:

  • General theory and approaches for scale coupling (theoretical concepts, structure formation, phase transitions, coarse graining – back mapping, adaptive resolution concepts, simultaneous coupling schemes, mesoscopic models with particles or fields….)
  • Interaction potentials, force fields (consistent definitions, parameterization of force fields on all levels of description, transferability, quantum effects, local vs. nonlocal interactions….)
  • Dynamics near equilibrium (consistency at different levels of description, linking micro, meso- and macro-dynamics, different time scales at different degrees of coarse-graining….)
  • Strongly nonequilibrium systems (driven systems, growth processes, kinetics, dissipation mechanisms….)

There will be an associated conference Modeling Soft Matter:Linking Multiple Length and Time Scales to be held Jun 4-8, 2012. Further information will be posted when it becomes available. You need not be a program participant to attend the conference.