Line Strengths in Two-Electron Spectra

We consider configurations which are pure in any one of the coupling schemes $$LS, LK, j1K\enspace j1j2$$ . Formulae are given for line strengths of transitions between any two of these configurations. Certain sum rules are presented. Tables of line strengths, restricted to the five most common types of transition of the form np n′l′−np n″l″ are given.