The project involves exploratory synthesis together with physical characterization of metal-rich halides and, increasingly, chalcogenides of group 3 transition metals. The studies will feature a unique group of highly reduced compounds in which metal cluster and condensed cluster phases are stabilized by strongly bound, interstitial elements in nominal metal octahedra. The cluster hosts will include Scandium, Yttrium, and the lanthanides (R), halogens, the chalcogens, Sulfur, Selenium and Tellurium, with the interstitials usually being late transition metals. These cluster-interstitial combinations are in a general way related to local interactions present for interstitials in pure metal systems. Identification and characterization of new compounds, including phases known only by powder patterns, will be emphasized, especially for the new and novel metal-rich but electron-poor chalcogenides. Physical properties of interesting phases will be defined by crystal structure, electronic conductivity, magnetic susceptibility, and photoelectron spectroscopic measurements, and these will be augmented by extended-Huckel (band) calculations. % % % Pursuing new and unexpected chemistry and materials properties in metal-metal bonded compounds together with an understanding the nature of their bonding and physical properties expands the boundaries of what is possible in solid state chemistry. Ultimately such investigations will cover a wide range of new materials for which sufficient information and experience will allow broader systemization and reasonable predictions of new classes of functional materials. ***
