Calculation of Some ExcitedS2States of Lithium in Hylleraas Coordinates

Early calculations by James and Coolidge and more recent work by Larsson have treated the lithium ground state by expansions containing correlation factors of the form ${{\mathcal{r}}_{\mathrm{ij}}}^p$. Similar calculations of the first two excited ${}_{}{}^2{}_{}{}^{}S$ states are reported herein. Expansions of 22 and 18 terms, respectively, led to calculated nonrelativistic energies (in a. u.) of - 7.3535 and - 7.3175, as compared to relativistically adjusted experimental values of - 7.3541 and - 7.3185. A brief discussion is given of feasibility of similar calculations for more complex atoms.