Qualitative Aspects of Resonances in Electronmdash;Atom and Electronmdash;Molecule Scattering, Excitation, and Reactions

摘要

A qualitative description of various types of resonant states of atoms and molecules is given. The classification is seen to be useful in explaining and discussing experimental phenomena. It is found that, as in nuclear physics, atoms and molecules exhibit both singlehyphen;particle and corehyphen;excited resonant states. A general quasistationary method is presented which can be used to calculate the energies of the resonant states from intuitively selected trial functions. The Feshbach technique is used for formal justification of this method, and the relation of the quasistationary method to other published resonance calculations is discussed. Experiments are suggested to test the ideas presented.