A theoretical study, using the diffusion quantum Monte Carlo method had estimated the formation energy of a neutral Si self-interstitial to be 4.9eV. This value was 50% higher than the LDA result of ab initio calculations. It was shown here that gap and finite-size corrections, that had been proposed in the past, might explain this difference provided that the defect levels for point defects were well known. It was shown that B-interstitial systems were more difficult to treat in this way.

Diffusion in Silicon and the Predictive Power of ab initio Calculations. W.Windl: Physica Status Solidi B, 2004, 241[10], 2313-8