The ring-hexavacany in silicon: A stable and inactive defect

Abstract
Molecular dynamics simulations as well as ab initio and near ab initio Hartree-Fock calculations in crystalline silicon predict that the configuration of the hexavacancy that has a hexagonal ring missing from the crystal is remarkably stable. The energetics imply that it does form and is more likely to grow than to dissociate during heat treatments. Further, the energy eigenvalues and the charge distribution imply that it has no electrical or optical activity. However, it is a large void in the crystal and could be an efficient gettering center and a precursor of extended defects.