Ionization energies of doubly and triply ionized lanthanides by a linearization technique

Linear intraseries correlations of the ionization energies I3 and I4 are developed for the gaseous lanthanides. Good agreement is found between our results and previous results, where these ionization energies are more precisely known. Where these ionization energies were less precisely known, we interpolate more precise values, and we offer one explanation of why some of the previous values are slightly higher than our values.