Energy Bands of CsI (Green's Function Method)

Energy bands of CsI in the s.c. and f.c.c. modification have been calculated using the full relativistic Green's function method. Results for ionic and atomic potentials are presented. The splitting of d‐like conduction bands, which is characteristically different in both crystal modifications, is explained by tight‐binding considerations. The binding energy of the Γ 8 − – Γ 6 + excition turns out to be about 30% larger in f.c.c. than in s.c. CsI. The calculated band separations and deformation potentials for hydrostatic pressure are in good agreement with experimental results.