Electronic States of Alkali Metals Studied by the DV-Xα Cluster Method

Abstract

The discrete variational (DV) Xα method is applied to investigate the electronic structure of alkali metals. The structure of energy levels of large cluster has a similarity to the density-of-states of metallic system of the same elements if the contribution of surface atoms is removed. Decomposition of the density-of-states at the Fermi energy into the partial waves shows strong p character for Li, nearly equal s and p contributions for Na and nearly equal s, p and d components for K, Rb and Cs. The calculated density-of-states is compared favorably with X-ray absorption spectrum of K, Rb and Cs. The effect of the d state near the edge of X-ray absorption spectrum is found serious, in particular for Cs.