Valence photoelectron spectra of Na, K, Rb and Cs with s or p outermost electron: Evolution of the states from LS-coupling to jK-coupling

The development of the fine structure of the np5(n+1)s and np5(n+1)p (n=2 in Na, n=3 in K, n=4 in Rb, n=5 in Cs) configurations of alkali atoms ions from LS-coupling to jK-coupling has been studied by comparing the experimental photoelectron spectra with the results obtained with analytical LS-coupling and jK-coupling models.