A simple model for a theoretical study of the spectral line shifts of alkali atoms attached to helium nanodroplets

摘要

The lowest s -> s line shifts of the alkali atoms Li and Na attached to He-4 nanodroplets have been estimated using ab initio quantum chemical methods with a physically viable cluster model of alkali atom (Li/Na) on the surface of helium atoms. First, detailed non-relativistic calculations are made using size extensive Configuration Interaction (CIS(D)) yielding the line shift of the 2s -> 3s and 3s -> 4s transitions of Li and Na in good agreement with available experimental results. Next, relativistic density functional calculations were performed yielding consistent results for the line shifts compared to the non-relativistic estimates and in good agreement with experimental results. (C) 2015 Elsevier B.V. All rights reserved.