Electronic structure of solids with WIEN2k

Aspects of the progress over the last 40-50 years in calculating the electronic structure of solids and surfaces are sketched in the context of collaboration on the code now called WIEN2k. Different facets that are relevant for material sciences are discussed, ranging from quantum mechanics to the augmented plane wave (APW) method, as well as improvements in computer hardware and algorithms and related numerical accuracy. In this long period, the complexity and realism of applications to condensed matter systems has significantly increased and many properties which are closely related to experiments can now be calculated. This progress is illustrated by the fact that WIEN2k now is used worldwide by more than 1600 groups. The major steps in this development are illustrated for a few selected examples.