In this project in the Physical Chemistry program of the Chemistry Division, Prof T. Darrah Thomas of the Oregon State University will engage in a study of the inner-shell excitation and deexcitation of molecules by electron spectroscopy. Of primary interest is the development of facilities to perform Auger-photoelectron coincidence spectroscopy in the gas phase and on using zero-kinetic energy spectroscopy to determine the lifetimes of core-ionized molecules. In addition, the relationship between the inner-shell ionization energies and other chemical properties will continue to be investigated. In Auger-photoelectron spectroscopy the spectrum is measured in coincidence with photoelectrons of selected energy. This technique makes it possible to study the deexcitation pathways of a single, selected excited state and thereby it is an important aid in the understanding of complex Auger spectra. This technique has heretofore been applied only to solids. The aim of this project is to extend its applicability to systems in the gaseous phase. Core-ionization energies can be related directly to the factors that influence a number of chemical properties. Research in the two areas of Auger photoelectron spectroscopy and core-ionization energies will contribute to a better understanding of chemical phenomena.