Force-matched embedded-atom method potential for niobium

TL;DR

This paper develops a new embedded-atom method potential for niobium, enabling accurate large-scale simulations of its deformation and phase changes by fitting to DFT data and validating against experimental results.

Contribution

It introduces the first reliable EAM potential for niobium, optimized to DFT data, with high transferability and accuracy for various properties.

Findings

DFT surface energies are reproduced within 4%

Stacking-fault energies differ by less than 15% from DFT

Melting temperature within 2% of experimental value

Abstract

Large-scale simulations of plastic deformation and phase transformations in alloys require reliable classical interatomic potentials. We construct an embedded-atom method potential for niobium as the first step in alloy potential development. Optimization of the potential parameters to a well-converged set of density-functional theory (DFT) forces, energies, and stresses produces a reliable and transferable potential for molecular dynamics simulations. The potential accurately describes properties related to the fitting data, and also produces excellent results for quantities outside the fitting range. Structural and elastic properties, defect energetics, and thermal behavior compare well with DFT results and experimental data, e.g., DFT surface energies are reproduced with less than 4% error, generalized stacking-fault energies differ from DFT values by less than 15%, and the melting temperature is within 2% of the experimental value.