Theoretical investigations of the electronic and optical properties of pure and alkali metal intercalated 1T-VSe2

We report calculations of the electronic properties of the layered 1T-VSe2 and its intercalated alkali metal compounds NaVSe2, KVSe2 and CsVSe2, using the full potential linear augmented plane wave method. Our calculated band structures are in qualitative agreement with previous calculations with minor differences in the amount of the overlap between valence and conduction bands. We find a strong hybridization between V-d and Se-p states for all compounds. For the intercalated compounds the hybridization of alkali-p states with V-d and Se-p states depends on the alkali metal. We have calculated the anisotropic frequency-dependent dielectric function to ascertain the effect of intercalating IT-VSe2 with alkali metals on the optical properties. (C) 2004 Elsevier B.V. All rights reserved.