Interatomic potentials for Al and Ni from experimental data and ab initio calculations

摘要

New embedded-at0m potentials for Al and Ni have been developed by fitting to both experimental data and the results of ab initio calculations. The ab initio data were obtained in the form of energies of different alternative computer-generated crystalline sturctures of these metals. The potentials accurately preroduce basic equilibrium properties of Al and Ni such as the elastic constants, phonon dispersion curves, vacancy formation and migration energies, stacking fault energies, and surface energies. The equilibrium energies of various alternative structures not iinducded in the fitting database are caclulated with these potentials. The results are compared with predictions of total-energy tight-binding calculations for the same structures. The embedded-atom potentials correctly reporoduce the structural stability trends which suggests that thjey are transferable to different local environments encountered in atomistic simulations of lattice defects.