Orbital-Free Density-Functional Theory Simulations of Displacement Cascade in Aluminum

Here, we report orbital-free density-functional theory (OF DFT) molecular dynamics simulations of the displacement cascade in aluminum. The electronic effect is our main concern. The displacement threshold energies are calculated using OF DFT and classical molecular dynamics (MD) and the comparison reveals the role of charge bridge. Compared to MD simulation, the displacement spike from OF DFT has a lower peak and shorter duration time, which is attributed to the effect of electronic damping. The charge density profiles clearly display the existence of depleted zones, vacancy and interstitial clusters. And it is found that the energy exchanges between ions and electrons are mainly contributed by the kinetic energies.