Design and Validation of an Angular Dependent Interatomic Potential for Nickel

Abstract Classical interatomic potentials for Nickel are essential for large-scale atomistic simulations, yet many existing models suffer from thermal-inconsistency biases by mixing zero-Kelvin predictions with finite-temperature experimental data. To address this, a new angular-dependent potential for elemental Nickel was developed and validated, parameterized using a comprehensive first-principles Density Functional Theory reference dataset. The dataset included diverse ground-state, strained, high-temperature, surface, and defect configurations. Optimized via force-matching, the potential shows high fidelity to the Density Functional Theory training data. Its performance was benchmarked against experimental data and three other representative interatomic potentials, demonstrating excellent agreement for the lattice constant, bulk modulus, longitudinal elastic constants, and phonon dispersion relations. While it shows strong agreement for most properties, deviations were observed in the shear elastic constant, intrinsic stacking-fault energy, and vacancy energetics. This angular-dependent potential offers a robust alternative at an intermediate computational cost, suitable for large-scale simulations where lattice dynamics and equilibrium bulk properties are critical.