LAUSR

Point defects significantly change electronic properties of alkali halides and thereby enhance their reactivity. However, both the experimental and theoretical description of defects such as the $F$ center and the $M$ center are still far from complete, in particular for the less common bromides. A self-consistent dielectric-dependent global hybrid and plane-wave approach is employed for a comparative theoretical study of the electronic properties of NaCl, KCl, NaBr, and KBr bulk and (100) surface, both perfect and defective. For these systems, a zero-point renormalization was calculated to account for electron-phonon interaction and enhance comparability with the experiment. We focus on anion vacancy defects, the so-called $F$ and $M$ centers. The methodology employed is capable of reproducing measured defect level energies, electronic band gaps, ionization energies, and electron affinities within experimental errors. A general trend of the $F$ center defect level energy with respect to the lattice parameter is found. The results for both the $F$ and the $M$ center of KCl agree with findings from magnetic resonance experiments. The defect orbitals are analyzed and virtual states of the defect electron are identified.