Long-range empirical potential model: Application to fcc transition metals and alloys

Abstract

Under the framework of the second moment approximation of tight-binding theory, a long-range empirical potential (LREP) is developed for transition metals in the present study and successfully applied to Cu, Ag, Au, Ni, Pd, Pt, and their alloys. It is found that the LREP model has successfully overcome the structural stability problem of traditional short-range potentials and resolved the energy and force jumps taking place in previous long-range potentials at cutoff radius without any truncated function. Importantly, the equations of state derived by the LREP model for the metals and alloys are in excellent agreement with those obtained from the Rose equation and experiments, indicating that the present model can relevantly predict the properties of metals and alloys at nonequilibrium state. Furthermore, the other calculated properties, such as the lattice constant, cohesive energy, elastic constants, and phonon spectra, also match well with those obtained by experiments or ab initio calculations.