Atomic frames and optical characteristics of semiconductors with defect chalcopyrite structure

Systematic investigation of the electron core contribution to linear optical responce of crystals with defect chalcopyrite structure (cadmium thiogallate and selenogallate) is carried out. Account of atomic core contribution results in decrease of refractive index of ordinary (n0) and extoordinary (nsub(e)) wave by 5-8% along the whole transmisson band and has no sufficient effect on the double refraction value Δn=nsub(o)-nsub(e) and position of lambda0 isotropy point. Calculated lambda0 values are in the rage of (0.475-0.5) and (0.575-0.6) μm for cadmium thiogallate and selenogallate, respectively