Semiempirical studies of atomic structure: Progress report, April 2, 1986-February 15, 1987

Studies of the structure and properties of highly ionized many electron atoms are proceeding through a combination of experimental measurements, semiempirical modeling and systematizations, and ab initio theoretical calculations. Atomic systems which have both many electrons stripped away and many electrons remaining often occur as contaminants or controlled impurities in high temperature plasmas, but information on their spectroscopic properties remains fragmentary. Spectroscopic classifications require accuracies exceeding parts per million, which cannot be achieved by standard ab initio methods for these complex systems. Semiempirical systematizations of high precision data can provide these accuracies, and an increasing base of this data is becoming available through studies utilizing fast ion beam excitation, laser and tokamak produced plasmas, astrophysical sources, and conventional spectroscopic sources. This program seeks to acquire, systematize, and parametrize large blocks of data along, e.g., isoelectronic, homologous, isoionic, isonuclear, Rydberg, and yrast series for the exposition of predictive empirical regularities. Trends revealed are then tested through well chosen experimental measurements, and ab initio methods are used to seek quantitative understanding of the empirical regularities