Scope and Aim of the School

Computational techniques in the realm of molecular sciences, which cover much of those parts of physics, chemistry and biology that deal with molecules, are well established in terms of extremly powerful but highly specialized approaches such as band structure calculation, quantum chemistry and biomolecular simulation, respectively. This is, for instance, nicely demonstrated by the series of NIC Winter Schools that was devoted over the years to several well-defined and mature areas like "Quantum Chemistry" (2000), "Quantum Many-Body Systems" (2002),"Soft Matter" (2004), or "Nanoscience" (2006).

However, more and more problems tackled in experiments, which became truely molecular in the sense of accessible length and time scales using scanning probe techniques and femtosecond spectroscopy to name but two prominent examples, require to cover several aspects at once. In most cases it is various length-scales and/or time-scales covered by separate computational techniques that need to be intimately connected, or at least traversed, in order to establish a fruitful crosslink between research in the real laboratory and in "virtual lab". This is right at the heart of what the Winter School series aims at addressing in 2009 after having covered the state-of-the-art in many specialized areas that is documented by the publications of several elaborate volumes of Lecture Notes in the NIC publication series (available free of charge for download).

In a nutshell, the Winter School 2009 deals with what we would like to call "eclecticism in simulation". The definition of eclecticism currently found in Wikipedia, i.e. "a conceptual approach that does not hold rigidly to a single paradigm or set of assumptions, but instead draws upon multiple theories, styles, or ideas to gain complementary insights into a subject, or applies different theories in particular cases" although not (yet) with reference to the Sciences but only to Architecture, Music and Psychology among others, captures perfectly the situation that we encounter.

In particular three strings of themes will be covered focusing on how to deal with hard matter, soft matter, and bio matter when it is necessary to cope with disparate length and time scales. Therein aspects like coarse graining of molecular systems and solids, quantum/classical hybrid methods,embedding and multiple time step techniques, creating reactive potentials, multiscale magnetism, adaptive resolution ideas or hydrodynamic interactions will be discussed in detail. In addition, another string of lectures will be devoted to the genuine mathematical and the generic algorithmic aspects of multiscale approaches and their parallel implementation on large, multiprocessor platforms including techniques such as multigrid and wavelet transformations. Although this is beyond what can be achieved in a very systematic fashion given the breadth of the topic, introductions into fundamental techniques such as molecular dynamics, Monte Carlo simulation, and electronic structure (total energy) calculations in the flavor of both wavefunction--based and density--based methods will be provided.

It is clear to the organizers that multiscale simulation is a rapidly evolving and multifaceted field that is far from being coherent and from becoming mature in the near future given unresolved challenges of connecting, in a conceptually sound and theoretically clean fashion, various length and time scales. Still, we think that time is come to organize a Winter School on the very topic in order to provide at least a glimpse at what is going on to the upcoming generation.