A brief review was given of the key developments that have rendered theory quantitatively useful to experimentalists. Thus, over the past few decades, considerable progress had been achieved in the theoretical prediction of a wide range of properties of defects in semiconductors. Theory now routinely predicted accurate vibrational properties of defects, and thus aided the optical characterization of impurities, although the positions of gap levels had yet to be predicted with reliable accuracy. Super-cells much larger than in the past could be used to describe defect centers from first principles. Systems large enough to study the dynamics of extended defects could be handled at near to first-principles level.

Theory of Defects in Si and Ge - Past, Present and Recent Developments. S.K.Estreicher, D.Backlund, T.M.Gibbons: Thin Solid Films, 2010, 518[9], 2413-7