Non-local electron-phonon coupling in atomic scale simulations at room temperature in metals

The two temperature model (TTM) is commonly used in metallic crystals under irradiation to establish predictions beyond the Born-Oppenheimer approximation. Examining in normal conditions, the heat spike decrease in TTM we remarked that oddly the decrease rate is independent from electron conductivity when the thermal heterogeneity has size inferior to electron mean free path whilst for larger sizes the decrease is essentially driven by electron conductivity. An additional non-local coupling was found to be necessary to recover a relaxation time depending on the electron conductivity at all sizes, as expected for metals. A method is proposed to transfer the non-local contribution into molecular dynamics simulations. We check transferability of our method through the study of Au and Ni of which electronic properties differ significantly.