A modified form of the Tersoff empirical interatomic potential was proposed in order to improve the simulation of adatom behavior on surfaces. The modified form of the potential was consistent with local density approximation calculations of the surface electronic band structure of Si(001) 2 x 1. It was demonstrated that the addition of a screened Morse potential tail to the bulk Tersoff interaction, when tetrahedral coordination was disrupted, significantly improved the results. The surface structure was calculated and was shown to yield substantial differences with respect to the original potential form. In particular, anomalous abrupt variations in adatom bonding energy were eliminated and the probability of successful deposition of an adatom on a lattice site was increased.

J.Wang, A.Rockett: Physical Review B, 1991, 43[15], 12571-9