Interstitial Li and Na in ZnSe-pairing energies and lattice location

The authors review increasing evidence for the important role, for luminescence and for electrical properties, of Li and Na interstitials in ZnSe. It is emphasized that exact lattice location, i.e. which interstitial site is stable and the extent of pairing with acceptors, is also of importance. For this reason the authors have calculated these pairing energies The calculation has been done with a variant of the Mott-Littleton procedure, the CASCADE computational method.