Sparse random Fourier features based interatomic potentials for high entropy alloys

Abstract

Computational modeling of high entropy alloys (HEA) is challenging given scalability issues of Density functional theory (DFT) and non-availability of Interatomic potentials (IP) for molecular dynamics simulations (MD). This work presents a computationally efficient IP for modeling complex elemental interactions present in HEAs. The proposed random features-based IP can accurately model melting behaviour along with various process related defects. The disordering of atoms during the melting process was simulated. Predicted atomic forces are within 0.08 eV / Å of corresponding DFT forces. MD simulations predictions of mechanical and thermal properties are within 7% of the DFT values. High temperature self diffusion in the alloy system was investigated using the IP. A novel sparse model is also proposed which reduced the computational cost by 94% without compromising on the force prediction accuracy.