The plasmon excitations in small lithium clusters: A time-dependent density functional theory study

The formation of plasmon modes of small lithium clusters has been studied using time-dependent density functional theory. The plasmon excitation behavior of linear and three-dimensional lithium clusters are investigated by excitation spectra. For the linear lithium clusters, the excitation behaviors of plasmon modes are investigated along the chain length. The energies and the intensities of excitation peaks well develop in the longitudinal and transverse modes. For the three-dimensional lithium clusters, the symmetry effect on the plasmon modes is also discussed. The induced electron density in each plasmon mode shows a strong dependence on the size of clusters.