Ehrenfest dynamics with a time-dependent density-functional-theory calculation of lifetimes and resonant widths of charge-transfer states ofLi+near an aluminum cluster surface

Abstract

We present a time-dependent density-functional-theory (TDDFT) Ehrenfest dynamics approach to study the lifetime and the charge neutralization rate of a lithium ion near an aluminum cluster surface. The lifetime of the excited state as a function of the surface-atom distance can be determined, including the effects of level crossings, without prior quantitative information about the coupling between atomic levels and surface states. This method can be used to compute lifetimes of excited atomic states near a surface in both the weak- and the strong-coupling regions and in the avoided crossing region. Because TDDFT Ehrenfest dynamics is a mean-field theory, the wave function consists of contributions from several different excited states during the time propagation. The shortest lifetime is predicted near the region of the avoided crossing between the ${\text{Li}}^{+}\text{-Al}$ and the ${\text{Li-Al}}^{+}$ states.