Confined variational method applied to low-energy electron-lithium collisions

The confined variational method is employed to study low-energy electron collisions with a lithium atom, for energies below the $2p$ excitation threshold. The accuracy of the phase shifts has been markedly improved in our calculations. From these calculations, we obtain an electron affinity of 4985.6124 ${\mathrm{cm}}^{\ensuremath{-}1}$, in excellent agreement with experiment, validating the accuracy of the approach. A least-squares fit of the phase shifts to effective-range theory yields an $S$-wave scattering length of $A=3.02{a}_{0}$, where ${a}_{0}$ is the Bohr radius. These results provide a stringent benchmark for future theoretical and experimental investigations. In this study, the sum of all electron spins is considered to be zero.