Theory and calculation of excited-state wave functions and properties

This paper discusses the following. (1) A newly developed first-order theory of oscillator strengths (FOTOS) which has yielded accurate results for f values involving single and multiple excitations to discrete and autoionizing states. Near-FOTOS results are reported for the N I 2p3 4S0 ⟹ 2s2p4 4P, 2p23s 4P isoelectronic sequences, the B I 2s22p 2p0 ⟹ “2s2p2” 2S transition, and the N II 2s2p3 1P0 lifetime, which are in good agreement with experiment, in contrast to earlier results. (2) The semiquantitative predictive capability of FOTOS in identifying the important correlations in photoelectron spectroscopy, photoionization of rare gases, and molecular transitions. (3) Improvements in the accuracy and efficiency of the correlation procedure which has now been applied to species as large as cesium. Positions of resonances in He− and Li and binding energies of K+ and K are reported. (4) A new theorem which suggests nonexponential decays might be observed for autoionizing states sufficiently close to the ionization potential (perhaps O I 2p33s3P0). (5) The properties and means of theoretically and experimentally searching for bound states in the continuum, whose existence appears improbable.