Epitaxial thin film ferroelectrics have potential application in a wide range of current and emerging microelectronic technologies, including static random access memories, high dielectric constant capacitors, pyroelectric detectors, and optical frequency doublers and waveguides. The proposed research focuses on the theoretical understanding and experimental verification of equilibrium and metastable structures realizable in ferroelectric thin films. The collaboration between Wolfgang Pompe of the Technical University of Dresden benefits from the experimentally-based approach of the PI and the theoretically- based approach of Pompe.