Magnetism and spectroscopy; where does theory stand?

In this talk it is presented where theory now stands in describing the electronic structure and materials properties of magnets in particular. The basic ideas of density functional theory (DFT) will be reviewed and examples will be given of how electronic structure based on DFT reproduces observations. Focus will be paid to magnetic excitations and ultrafast phenomena of materials in 3D as well as 2D geometry. Finally, complications of the electronic structure due to correlations and multiconfiguration effects will be discussed and how spectroscopy of such systems can be reproduced.