The dimer method was used to search for possible transition states of interstitials and small interstitial clusters in SiC. The method used only the first derivatives of the potential energy to find saddle points without knowledge of the final state of the transition. The possible migration pathway for the C interstitial was found to consist of the first neighbor jump via a Si site or second neighbor jump, but the relative probability for the second neighbor jump was very low. It was also questioned whether migrating interstitial clusters could thermally change their direction, and the activation energies and corresponding mechanisms for changing the direction of clusters were determined.

Finding Possible Transition States of Defects in Silicon-Carbide and Alpha-Iron using the Dimer Method. F.Gao, G.Henkelman, W.J.Weber, L.R.Corrales, H.Jónsson: Nuclear Instruments and Methods in Physics Research B, 2003, 202, 1-7