Abstract
Acceptor-bound holes in oxides often localize asymmetrically at one out of several equivalent oxygen ligands. Whereas Hartree-Fock (HF) theory overly favors such symmetry-broken polaronic hole localization in oxides, standard local-density (LD) calculations suffer from spurious delocalization among several oxygen sites. These opposite biases originate from the opposite curvatures of the energy as a function of the fractional occupation number , i.e., in HF and in LD. We recover the correct linear behavior, , that removes the (de)localization bias by formulating a generalized Koopmans condition. The correct description of oxygen hole localization reveals that the cation-site nominal single acceptors in ZnO, , and can bind multiple holes.
- Received 17 February 2009
DOI:https://doi.org/10.1103/PhysRevB.80.085202
©2009 American Physical Society