  This paper gives a summary of basic concepts of density-functional theory
(DFT) and its use in state-of-the-art computations of complex processes in
condensed matter physics and materials science. In particular we discuss how
microscopic growth parameters can be determined by DFT and how on this basis
macroscopic phenomena can be described. To reach the time and length scales of
realistic growth conditions, DFT results are complemented by kinetic Monte
Carlo simulations.
