Many-body effects in bcc metals: An embedded atom model extension of the modified Johnson pair potential for iron

In this work, we generalize a many-body extension of pairwise interatomic potentials originally proposed by Baskes [Phys. Rev. Lett. 83, 2592 (1991)], in particular, showing how a pair potential interacting with multiple near neighbor shells may be extended to an embedded atom form without changing the cohesive energy or lattice constant. This is important for parametric studies of interatomic potentials, particularly how elastic constants affect other properties. Specifically, we apply this to the modified Johnson potential, a pair potential for Fe that has been used extensively for understanding liquid and amorphous metals.