Solid state calculations using WIEN2k

To study solid materials on the atomic scale one often starts with an ideal crystal at zero temperature and calculates its electronic structure by means of density functional theory (DFT). This allows a quantum mechanical treatment of the physics that underlines properties such as relative stability, chemical bonding, relaxation of the atoms, phase transitions, electrical, mechanical, optical or magnetic behavior, etc. For the solution of the DFT equations several methods have been developed. The linearized-augmented-plane-wave method is one of the most accurate methods. It is embodied in the computer code––WIEN2k––which is now used worldwide by more than 500 groups to solve crystal properties on the atomic scale (see www.wien2k.at). Nowadays calculations of this type can be done––on sufficiently powerful computers––for systems containing about 100 atoms per unit cell. Chromium dioxide CrO2 is selected as a representative example using both, bulk and surface structures. References to other applications are given.