Abstract
Analytical wavefunctions for the first three 2 D states of lithium isoelectronic atomic sequence have been obtained using a split‐shell core function plus a generalized orbital form for the outer electron. Values of ionization potentials for the outer electron in the three 2 D states have been calculated by the ``frozen‐core'' approximation, and these compare very well with experimental results. The use of an extended wavefunction for the lowest 2 D state obtained by superposing (2p)2 1 S function on the split‐shell function for the core leads to energy values within 0.01 a.u. of experimental values.