Angular momentum coupling, potential curves and radiative selection rules for heavy diatomic molecules, with particular reference to Kr 2 and Kr 2+

Abstract

The coupling of electronic orbital angular momentum, spin, and molecular rotation of diatomic molecules is summarized, with emphasis on heavy molecules where the spin-orbital interaction is not small. The symmetry properties of diatomic wavefunctions are discussed and tabulated. The building up of molecular electronic states from states of the separated atoms, from states of the united atom, and from molecular orbitals is also explained. These principles and other data are applied to the construction of potential energy curves for Kr 2 and Kr 2 +, following the example of Mulliken for Xe 2 and Xe 2 +. Finally, the electric dipole selection rules for radiative transitions between electronic states are summarized and applied to Kr 2.