An extensive first-principles study was made of the pressure dependence of the formation enthalpies of all the known vacancy and self-interstitial configurations in silicon, in each charge state from –2 through +2. The neutral vacancy was found to have a formation volume that varied markedly with pressure, leading to a remarkably large negative value (–0.68 atomic volumes) for the zero-pressure formation volume of a Frenkel pair (V+I). The interaction of volume and charge was examined, leading to pressure-Fermi level stability diagrams of the defects. Finally, the anisotropic nature of the lattice relaxation around the neutral defects was quantified.

First-Principles Calculation of Intrinsic Defect Formation Volumes in Silicon. S.A.Centoni, B.Sadigh, G.H.Gilmer, T.J.Lenosky, T.Díaz de la Rubia, C.B.Musgrave: Physical Review B, 2005, 72[19], 195206 (9pp)