ELECTRONIC STRUCTURE OF THE ALKALINE EARTH HALIDES

Recently the entire CaX (X = F, Cl, Br, and I) series has been examined spectroscopically. All, except $CaCl^{1}$, have been studied using cw, single-mode, single-resonance and optical-optical double resonance techniques in our laboratory. The transitions involve a non-bonding $Ca^{+}$ electron, so the ionic states for each molecule all have very similar potential curves. These curves will be compared using Rittner-type $models^{2}$ and concepts from ligand field theory. The spectroscopic parameters, particularly $p, q, \\gamma$, and A and radiative lifetimes are interpreted on the basis of a simple hydrogenic-atom orbital picture. Periodic correlations will be described.