Nucleation of Supercooled Liquid Aluminum: an First-Principles Molecular Dynamics Study Based on Orbital-Free Density Functional Theory

Abstract: Nucleation is very common physical phenomena that occur at the microscopic scale. However, due to the presence of nucleation barriers, the time scale of nucleation is usually much longer than that of microscopic particle dynamics. These characteristics make it significantly challenging to study nucleation experimentally, theoretically, or computationally. In this work, the authors explore the significance and feasibility of applying first-principles calculations based on orbital-free density functional theory (OFDFT) to simulate nucleation in supercooled liquids. To analyze the performance of OFDFT in simulating nucleation in supercooled liquids, the authors employ orbital-free density functional theory molecular dynamics (OFDFT-MD) to compute the melting point of aluminum and simulate nucleation in supercooled liquid aluminum. By utilizing GlassViewer, an order parameter calculation software for nucleation problems developed by the authors, the evolution of the bond-orientational order (BOO) parameters and the mean first-passage time (MFPT) are calculated to analyze the changes of local atomic structures during the nucleation processes and the nucleation kinetics parameters of precursors. The results are then compared with those obtained using the embedded atom method (EAM) semi-empirical potential. The results indicate that OFDFT can provide relatively reliable melting points, and the predicted nucleation parameters are consistent with the results obtained using the EAM potential. This work demonstrates the feasibility of employing OFDFT for simulating nucleation in supercooled liquids, enabling the exploration of the effects of electronic structures and electromagnetic fields on nucleation processes in supercooled liquids using this first-principles approach.