Empirical construction of interatomic potentials for studies of grain boundaries and other crystal defects: Pure metals and binary alloys

It is first argued that pair potentials are physically meaningful if they are regarded as describing interaction between atoms embedded in an environment of similar density as that for which their derivation was made. These potentials are capable of describing structural aspects of lattice defects but not the cohesive properties. Guidelines for determination of the shape of potentials and an empirical scheme for their construction in pure metals is then outlined. It is shown that this method when applied to simple metals leads to potentials similar to those obtained on the basis of a pseudopotential theory and extension of this scheme to other metals is discussed. An empirical scheme of construction of potentials for binary alloys is then briefly described. It is shown that concentration dependences of elastic constants and lattice stability evaluated using these potentials agree with experimental data and thus these potentials are suitable for studies of defects in binary alloys.