They will measure soft x-ray emission spectra excited by light from the low energy storage ring of the National Synchrotron Light Source at Brookhaven National Laboratory. The measurements are made with a spectrometer facility recently constructed with support from NSF, and the three institutions participating in the research (Univ. of Tenn., National Bureau of Standards, and the Oak Ridge National Laboratory). The spectrometer facility is unique in its use of photon excitation, its wide energy range (100-1000 eV photons), high resolution, and superior measuring efficiency. X-ray emission spectroscopy permits the detailed study of the electronic states of elements, of individual components of compounds and alloys, and of impurities, clusters and minor contituents imbedded in solid systems. It is less surface sensitive than electron spectroscopies, and when combined with photon excitation, is useful for the study of fragile compounds that are damaged by electron excitation. Several experiments are planned: studies of light metal alloys, Boron alloys and compounds, high Tc superconducting alloys, semiconducting compounds, rare gas solids, clusters imbedded in various solid matrices, and multilayer systems.