  QCDFT is a multiscale modeling approach that can simulate multi-million atoms
effectively via density functional theory (DFT). The method is based on the
framework of quasicontinuum (QC) approach with DFT as its sole energetics
formulation. The local QC energy is calculated by DFT with Cauchy-Born
hypothesis and the nonlocal QC energy is determined by a self-consistent
embedding approach, which couples nonlocal QC atoms to the vertices of the
finite-elements at the local QC region. The QCDFT method is applied to a
nanoindentation study of an Al thin film in the presence and absence of Mg
impurities. The results show that the randomly distributed Mg impurities can
significantly increase the ideal and yield strength of the Al thin film.
