Towards exakt correlation in extended systems

During the last decades, Computational Science has firmly established its role as an important research tool complementing experimental and theoretical investigations. Materials Science and especially the novel field of nano-materials is one of the disciplines where computer simulation methods have played a particularly important role. Progress has been so fast that many current applications could not have been realized five years ago and were hardly dreamed of twenty years ago. Although this development has been facilitated by a rapidly increasing computer performance, the impact of novel theoretical methods in quantum mechanics and statistical mechanics, of improved computational algorithms and of their implementation in highly efficient computer codes has been even more important. With the widening application of computational methods to problems of both fundamental science and modern technology, Computational Materials Science now faces new challenges: (i) The prediction of groundstate total energies and of activation energies of chemical reactions and phase transformations must achieve chemical accuracy (i.e. a maximum error of about 1 kcal/mol) for real materials. This requires a substantially improved treatment of many-electron correlations. Here the recent development in the molecular quantum- chemistry has opened new routes, but to achieve the same goal for solids is much more difficult. (ii) To maintain the contact with modern experimental Materials Science, the functionality of the existing computer-simulation codes must be extended detailed predictions of materials properties that can be measured by modern electronic, optical or magnetic spectroscopies in weak and strong fields, as well as the simulation of electronic transport properties must become possible. (iii) Even with high-performance computers, the time and lengths scales accessible in the computer-laboratory are many orders of magnitude below those of real-world problems. To bridge these gaps requires the development of multi-scale simulation methods. Scientists at the two large universities in Vienna, the University of Vienna and the Vienna University of Technology, have made important contributions to the recent progress in Computational Materials Science. They now intend to combine their forces in the proposed Special Research Program. The intention is to confront the three challenges listed above and to consolidate the role of Vienna as one of the leading centres in this field.