Density functional theory

Density functional theory (DFT) is the most detailed “microscope” currently available to glance into the atomic and electronic details of matter. A variety of mature DFT codes are nowadays available to the materials science community. The codes are based on different choices of basis sets, potentials, exchange-correlation functionals, and algorithms for solving the Schrödinger equation. In our group we employ the Vienna ab initio simulation package (VASP).

Kohn-Sham equations overlaid with the DFT implementations used in our studies. Dispersion interactions are usually considered by means of the DFT-D2 method of Grimme (not shown here)

For many applications in materials science, the availability of a basic code for solving the Schrödinger equation is not sufficient; the resulting energies, wave functions, and electron and spin densities are merely the starting point for the calculations of many different materials properties. In order to yield a comprehensive description of materials and dynamic modelling of time-dependent processes in materials, one has to develop routines for the post-processing of DFT results (see e.g. our homemade computer code ELSA).