Correlation effects in electronic structure calculations

The programs of the Lorentz center are supported financially by NWO and FOM.

Additional funding for this workshop from the Lorentz Fund is gratefully acknowledged

The electronic structure of many materials can be described with a great accuracy within the framework of band structure based on the Local Spin Density Approximation (LSDA). Notable exeptions are the class of materials characterized by dominating electron-electron interactions, where conventional band structure theory fails rather badly. At the same time, much of the modern condensed matter physics deals with the phenomena occuring in these strongly correlated electron systems: heavy fermion metals, (doped) Mott-Hubbard insulators, cuprate superconductors etc. Substantial progress has been achieved in the qualitative understanding of the nature of the strongly correlated electronic state. We refer in particular to the fact that a variety of spectroscopic properties of 3d and 4f systems could be explained in terms of Hubbard-type model Hamiltonians.

The information needed for this kind modelling (Hubbard model parameters, tight binding parameters) can now be extracted from conventional LSDA calculations. Such situation clearly requries development of methods, which could combine both approaches: LSDA and model Hamiltonian calculations, and many researchers are now working in this direction.

Laste years several very promising methods were proposed and some of them have already reached the level of well developed calculation schemes, which can be used for determination of the electronic structure of real materials.

The purpose of the workshop is to give an opportunity to exchange information on the latest achievements between people working in this field. The emphasize will be on LDA+U and LDA+DMFT (Dynamical Mean-Field Theory) methods