Orbital-free density functional theory simulations of dislocations in aluminum

The core structure of screw and edge dislocations in fcc Al was investigated using orbital-free density functional theory (OF-DFT). Detailed calibrations of kinetic energy density functionals (KEDFs) and local pseudopotentials were performed to reproduce accurately the energies of several phases of bulk Al, as well as the elastic moduli and stacking fault energies of fcc Al. Thereafter, dislocations were modeled with both periodic and non-periodic cells containing a few thousand atoms, and the widths of the dissociated cores were extracted. The results are in good agreement with previous estimates from experiment and theory, further validating OF-DFT with non-local KEDFs as a seamless and accurate tool for simulating large features in main group, nearly-free-electron-like metals at the mesoscale.