The electronic structure of the lanthanide monohalides: A ligand field approach

Ligand field theory calculations of energy levels were performed for the neutral lanthanide monohalides by treating the molecular electronic states as Ln(+) free-ion levels perturbed by a ligand field X(-) (where Ln is an element of Ce through Yb and X is an element of F, Cl, Br, or I). The single-atomic-configuration approximation was used to compute the molecular energy levels with the lowest (maximum S-c, maximum L(c)) 4f-core Ln(+) atomic multiplet state for the majority of the Ln(+)X(-) superconfigurations. The density distributions of the bound electronic states of LnX up to their ionization limits were also calculated. These data are sufficient for determination of the electronic partition function. (C) 1996 Academic Press, Inc.