Hartree-Fock electronic structure calculations for free atoms and atoms immersed in an electron gas

Electronic structure calculations for free and immersed
atoms are performed in the context of unrestricted Hartree-Fock
theory. Spherical symmetry is broken, lifting degeneracies in
electronic configurations involving the magnetic quantum number
m. Basis sets, produced from density functional theory,
are then explored for completeness. Comparison to spectroscopic
data is done by applying configurational interaction of the appropriate
L and S symmetry. Finally, a perturbation technique by
Lowdin is used to couple the bound atomic states to a
neutral, uniform background electronic gas (jellium).