First-principles theoretical investigation of neutral vacancy-associated muonium center in silicon

To understand the nature of the recently discovered vacancy-associated cent er Mu(V) in silicon and its H counterpart V-H, we have carried out a first- principles Hartree-Fock cluster investigation mainly on the cluster Si(4)H( 12)Mu involving the muonium and the four silicon neighbors nearest to the v acancy in a neutral vacancy-associated environment, including lattice relax ation effects. Our results demonstrate that the neutral vacancy-associated model is able to explain the non-axial symmetry of the Mu(V) center through Jahn-Teller distortion and provides reasonable quantitative agreement with experimental hyperfine data. (C) 2000 Published by Elsevier Science B.V, A ll rights reserved.