Ab initio studies on the polarizability of lithium clusters: Some unusual results

The polarizability of lithium clusters was studied using ab initio as well as Density Functional Theory (DFT)-based methods. The electron correlation was found not to play any major role in the evaluation of polarizability of the lithium clusters, contrary to the case of sodium and other types of clusters. The theoretical methods used in the present study are not able to reproduce the unusual features in the size evolution of the polarizability observed experimentally. An interesting feature is that the polarizability of lithium clusters calculated by various methods at OK temperature is found to be higher than the experimental results measured at higher temperature, which is quite unusual. The significance of these issues is highlighted and the need of highly accurate DFT exchange-correlation functionals and ab initio methods in the study of the electronic properties of lithium clusters is emphasized. (c) 2005 Wiley Periodicals, Inc.