Phenomenological interatomic potentials for silicon, germanium and their binary alloy

A phenomenological potential is constructed for silicon, germanium, and their binary alloy. As in the modified embedded atom model (MEAM), the interatomic interactions are assumed to arise from the overlap of the electron wave functions. However, the calculation of energy is quite different in the two models. The proposed potential has seven adjustable parameters in contrast to ten or more in MEAM but gives perfect fit with the measured values of seven most important quantities for characterizing strained silicon: cohesive energy, equilibrium lattice constant, vacancy formation energy, Raman frequency, and the three elastic constants. The potential should be suitable for lattice statics calculations on strained silicon.

► Interatomic potential for Si, Ge, and SiGe; useful for modeling of strained Si. ► Includes the effect of electronic deformation and pair interaction. ► Seven adjustable parameters in contrast to ten or more in MEAM. ► Gives exact fit with values of lattice constant, cohesive and vacancy energy. ► Exact fits also for Raman frequency and the three elastic constants.