Comparison of interaction between Cu precipitate and vacancy in Fe using first-principle calculations and empirical N-body potential calculations

Body-centered cubic (bcc) Cu precipitates were investigated using empirical N-body potentials fitted to experimental values of face-centered cubic (fcc) Cu and using first-principle calculations, and the validity of applying these fcc empirical potentials to bcc Cu precipitates was examined. The atomic distance, cohesive energy and atomic volume in bcc Fe, fcc Cu and bcc Cu for the two calculations were compared. The magnitude correlation of the atomic distance was different for the two calculations. The vacancy formation energy in an Fe–Cu alloy system for the two calculations was compared and the dependence of the vacancy formation energy on the vacancy position was found to be the same for both calculations when the defect structure was fully relaxed.