Energy bands of the BCC metals rubidium and cesium

Energy bands of BCC rubidium and cesium are calculated for the first time using the full non-local but energy-independent Shaw's optimized model potential. The energy dependence of the potential is then included as first order perturbation. The effects of changing the model potential and of reversing the sign of the depletion charge d are reported. The Fermi energy E_F is calculated in all cases. Our results are compared with those obtained by other authors. The band gap at N is very small for both metals, except when all model potential parameters are increased considerably (50% to 100%).