Theoretical study of the spectral shift of the absorption line of Rb and Cs in liquid helium

Abstract

A combined and sequential use of Monte Carlo simulation and time-dependent density functional theory is made to obtain the excitation line shifts and widths of Rb and Cs embedded in liquid 4He. In each case calculations are made on 100 statistically uncorrelated configurations with Rb (Cs) surrounded by nearly 60 He atoms treated explicitly. Different basis sets and functionals are used for obtaining the blue shifts of the absorption lines 5s→5p of Rb and 6s→6p of Cs. Estimate of the line broadening is also made and results for both the shift and broadening are obtained in good agreement with experiment.