The central goal of my research is to develop an understanding of the correlation between composition, crystal structure and physical properties.Such knowledge is essential if solid state chemistry is to evolve from its current approach, which is largely empirical, toward a methodology based onthe concept of rational design. My aim is to develop the understanding that will allow certain classes of physical properties to be related to theircomposition and structure in a quantitative manner. This understanding is then utilized to design new materials with an eye toward technologicalapplications.