Optical properties of the alkali antimonide semiconductors Cs3SbCs3Sb, Cs2KSbCs2KSb, CsK2SbCsK2Sb and K3SbK3Sb

First principles calculations, by means of the full-potential linearized augmented plane wave method within the generalized gradient approximation, were carried out for the electronic and optical properties of the alkali antimonide compounds Cs3SbCs3Sb, Cs2KSbCs2KSb, CsK2SbCsK2Sb and K3SbK3Sb. The calculated lattice parameters and bulk moduli are in good agreement with the available data. The calculated band structures and density of states are in good agreement with previous calculations. The peaks and structures in the optical spectra are assigned to interband transitions. The calculated absorption coefficient for K3SbK3Sb and Cs3SbCs3Sb is in fairly agreement with the observed one.