Doubly Excited States in Lithium

Abstract

Doubly and triply excited states of lithium are considered in an effort to identify the energy levels responsible for the several narrow lines present in the optical spectrum of that element which are not classifiable in the normal singly excited spectra of that atom. Since most of these states are coupled to continuum states through the electrostatic interaction of the electrons and will thus have extremely short lifetimes, a majority of the multiply excited states can be excluded from consideration in identifying these narrow lines. The observed narrow spectral lines can be plasuibly identified on the basis of screening-theory estimates of the energies.