Projected general spin-orbital wavefunctions for three-electron systems

Abstract

Spin-projected Hartree-Fock calculations using general spin orbitals are performed on some S, P, D and F states of Li and on the ground states of its isoelectric ions with Z=4-10. The energy -7.447596 au is obtained for Li 22S, compared to -7.447565 au with the spin-optimized SCF method and -7.432727 au with the ordinary restricted Hartree-Fock method. Full configuration-interaction results for the same basis sets are also reported.