POSITRON-ANNIHILATION STUDIES IN CUCL

Electron-positron momentum densities in CuCl are calculated along two different crystallographic directions [001] and [110] with the use of the empirical pseudopotential method (EPM) coupled with the independen t particle method (IPM). The results exhibit features that are complet ely different from those observed in other III-V semiconductors. The d ip and valley observed in III-V compounds are replaced by peaks. These differences are attributed to the very shallow ''d'' states in copper .