Self-consistent treatment of effective electron correlation at localized dangling-bond defect states in silicon

A semiempirical local approach to the problem of electron correlation at localized defect states in solids is presented. The approach modifies any quantum-chemistry scheme by adding a certain correction to the Fock matrix, thus permitting one to obtain self-consistent correlation corrections to all ground-state parameters of the defect. The theory has been applied to the large-unit-cell models of the dangling-bond defects Si:V0 and Si:(VH3)-. The results of the calculations are useful for investigation of negative-U properties.