Development of a Fe-He interatomic potential based on electronic structure calculations

A new empirical Fe-He potential has been developed by fitting results obtained from first-principles calculations. Both the formation and relaxation energies of single He defects and small He clusters were accounted for in the fitting process. The new potential consists of a repulsive pair-potential term and a three-body interaction term, and was applied in combination with three commonly used iron interatomic potentials, and a potential describing the behavior of helium in vacuum. As an application of the new potential, the stability of He-vacancy clusters at zero temperature was evaluated. The calculated results were similar for all three Fe potentials, and the new potentials provide results that are more consistent with ab initio calculations than those obtained from previous Fe-He potentials.