Spin density and density moments for the lithium ground state

Accurate analytical charge and spin-electron densities for the lithium atom are obtained by using a systematic and reliable method recently developed and applied to closed-shell atoms. The convergence of the densities is analyzed in terms of well-defined improvements in the corresponding configuration-interaction wave functions, and mathematical criteria are used to test the stability of the densities and their derivatives. Fully converged results for one-electron properties and, in particular, for the Fermi-contact interaction are reported.