POINT-DEFECT COMPUTER-SIMULATION INCLUDING ANGULAR FORCES IN BCC IRON

An embedded-defect (ED) interatomic potential for Fe is presented. The ED model is based on the same physical description of interactions as the embedded atom method (EAM) but including angular-dependent many-body local terms. In this work, the ED potential is fitted to several Fe properties and is used to simulate the vacancy and various self-interstitial configurations. The pair and many-body contributions to the formation energy of the defects are calculated, as well as the corresponding relaxation volumes. The results are compared to those obtained with an EAM potential fitted to the same properties. The vacancy displacement field is studied in detail for both potentials. Anharmonic effects are assessed and correlated with the unrelaxed force pattern.