Hylleraas-Configuration Interaction study of the singlet S ground state of the negative Li ion
James S. Sims
In a previous work Sims and Hagstrom [J. Chem. Phys. 140,224312 (2014)] reported Hylleraas- Configuration Interaction (Hy-CI) method variational calculations for the neutral atom and positive ion singlet S ground states of the beryllium isoelectronic sequence. In this work the calculations have been extended to include the negative lithium ion singlet S ground state. The best non-relativistic energy obtained was -7.500 776 596 hartree.
Journal of Physics B-Atomic Molecular and Optical Physics