Theoretical studies of 1s2snl and 1s2pnl quartet levels of Li I

Abstract

Radiative properties of 1s2snl and 1s2pnl quartet levels of the neutral lithium atom are studied with the framework of a model-potential method, in which the K-shell electron is represented by a non-local effective potential. Convergence of configuration-interaction expansions for the wavefunctions is examined and it is found that continuum configurations often make important contributions. Two practical approaches to including such configurations are investigated. Transition wavelengths and probabilities, and radiative lifetimes, are calculated and compared with recent experimental values. Fine-structure-induced autoionisation of ⁴P and ⁴D⁰ levels above the 2s ³S ionisation limit of Li II is briefly discussed.