A state-of-the-art density functional theory study was made of intrinsic defects within rocksalt-structured silver halides; which were well known to favor Frenkel defect pairs over Schottky pairs. The defect structures and formation energies of the elementary point defects which were obtained by using the super-cell approximation were reported. In agreement with recent experimental results, it was found that the interstitial cation adopted a split-interstitial configuration, centered upon a lattice site. The effects of electron or hole trapping upon the defect centers in AgCl and AgBr were described; including formation energies, structures and spin localization.

Defect Structures in the Silver Halides. D.J.Wilson, A.A.Sokol, S.A.French, C.R.A.Catlow: Physical Review B, 2008, 77[6], 064115 (11pp)