Electronic Properties of Rare Gas Molecules (Invited paper)

In the theoretical bases for the electronic structures of excited homonuclear dimers, the molecular excited states are Rydberg in character, and their qualitative behavior can be deduced from that of the dimer ions. The derivation of accurate gas adiabatic potential curves in the full distance range requires calculations accounting not only for repulsive and overlap effects that induce the characteristic excimer well depths, but also for the long-range forces, and especially for dispersion. Attention is given to experimental results furnishing useful tests for the theoretical potential curves in a large domain of internuclear distances.